Citizendia
Your Ad Here

Tropocollagen triple helix.
Tropocollagen triple helix.

Collagen is the main protein of connective tissue in animals and the most abundant protein in mammals,[1] making up about 25% of the whole-body protein content. Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl Connective tissue is one of the four types of tissue in traditional classifications (the others being epithelial, Muscle, and Nervous tissue) Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands

Contents

Uses

Collagen is one of the long, fibrous structural proteins whose functions are quite different from those of globular proteins such as enzymes. Fibrous proteins, also called scleroproteins, are one of the two main classes of protein Quaternary structure (the other being Globular proteins. Globular proteins, or spheroproteins are one of the two main Protein classes comprising "globe" -like proteins that are more or less soluble in Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Tough bundles of collagen called collagen fibers are a major component of the extracellular matrix that supports most tissues and gives cells structure from the outside, but collagen is also found inside certain cells. In Biology, the extracellular matrix ( ECM) is the Extracellular part of animal tissue that usually provides structural support to the cells Collagen has great tensile strength, and is the main component of fascia, cartilage, ligaments, tendons, bone and teeth. Tensile strength \sigma_{UTS} or S_U is the Stress at which a material breaks or permanently deforms Fascia (făsh'ē-ə pl fas·ci·ae (făsh'ē-ē adj fascial (făsh'ē-əl (from Latin: a band is the Soft tissue component of Cartilage is a type of dense Connective tissue. It is composed of specialized cells called chondrocytes that produce a large amount of extracellular matrix In Anatomy, the term ligament is used to denote three different types of structures Fibrous tissue that connects Bones to other bones A tendon (or sinew) is a tough band of Fibrous connective tissue that usually connects Muscle to Bone and is capable of withstanding tension Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce Along with soft keratin, it is responsible for skin strength and elasticity, and its degradation leads to wrinkles that accompany aging. Keratins are a family of fibrous structural proteins; tough and insoluble they form the hard but nonmineralized structures found in Reptiles Birds The skin is the outer covering of living tissue of an animal (or plant A wrinkle is a ridge or crease of a surface It usually refers to folds on fabric or Clothes, or on the Skin of an organism the folds are generally random Ageing or aging (American English is the accumulation of changes in an organism It strengthens blood vessels and plays a role in tissue development. The blood vessels are part of the Circulatory system and function to transport Blood throughout the body Tissue is a cellular organizational level intermediate between cells and a complete organism It is present in the cornea and lens of the eye in crystalline form. The cornea is the transparent front part of the Eye that covers the iris, Pupil, and Anterior chamber. Eyes are organs that detect Light, and send signals along the Optic nerve to the visual areas of the brain In Materials science, a crystal is a Solid in which the constituent Atoms Molecules or Ions are packed in a regularly ordered repeating It is also used in cosmetic surgery and burns surgery. Plastic surgery is a medical specialty interested in the correction of form and function A burn is a type of Injury that may be caused by Heat, cold, Electricity, Chemicals, Light, Radiation, or

Industrial uses

If collagen is partially hydrolyzed, the three tropocollagen strands separate into globular, random coils, producing gelatin, which is used in many foods, including flavored gelatin desserts. Hydrolysis is a Chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions which may go on to participate in further reactions A random coil is a Polymer Conformation where the Monomer subunits are oriented randomly while still being bonded to adjacent Gelatin (also gelatine, from French gélatine) is a translucent colourless brittle nearly tasteless solid substance, extracted from the Food is any substance usually composed primarily of Carbohydrates Fats water and/or Proteins that can be eaten or drunk by an The most common culinary use for Gelatin is as a main ingredient in varieties of gelatin desserts. Besides food, gelatin has been used in pharmaceutical, cosmetic, and photography industries. [2] Collagen and gelatin are poor-quality protein since they do not contain all the essential amino acids that the human body requires - they are not complete proteins. An essential amino acid or indispensable amino acid is an Amino acid that cannot be synthesized de novo by the organism (usually referring to See also Protein in nutrition A complete protein (or whole protein) is a Protein that contains all of the Essential amino acids for Manufacturers of collagen-based dietary supplements claim that their products can improve skin and fingernail quality as well as joint health. However, mainstream scientific research has not shown any evidence to support these claims. Individuals with problems in these areas are more likely to be suffering from some other underlying condition rather than protein deficiency.

From the Greek for glue, kolla, the word collagen means "glue producer" and refers to the early process of boiling the skin and sinews of horses and other animals to obtain glue. An animal glue is an Adhesive that is created by prolonged boiling of Animal Connective tissue. A tendon (or sinew) is a tough band of Fibrous connective tissue that usually connects Muscle to Bone and is capable of withstanding tension The horse ( Equus caballus) is a hoofed ( Ungulate) Mammal, one of eight living species of the family Equidae. Collagen adhesive was used by Egyptians about 4,000 years ago, and Native Americans used it in bows about 1,500 years ago. This article is about the country of Egypt For a topic outline on this subject see List of basic Egypt topics. Native Americans in the United States are the indigenous peoples from the regions of North America now encompassed by the continental United States A bow is a Weapon that projects arrows powered by the elasticity of the bow The oldest glue in the world, carbon-dated as more than 8,000 years old, was found to be collagen — used as a protective lining on rope baskets and embroidered fabrics, and to hold utensils together; also in crisscross decorations on human skulls. Radiocarbon dating is a Radiometric dating method that uses the naturally occurring Radioisotope Carbon-14 (14C to determine the age of Embroidery is the Art or Handicraft of decorating fabric or other Materials with designs stitched in strands of thread or A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn. This is a list of eating and serving implements. Chopsticks Drinking straws * Fork Knife Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus [3] Collagen normally converts to gelatin, but survived due to the dry conditions. Animal glues are thermoplastic, softening again upon reheating, and so they are still used in making musical instruments such as fine violins and guitars, which may have to be reopened for repairs — an application incompatible with tough, synthetic plastic adhesives, which are permanent. A thermoplastic is a Plastic that Melts to a liquid when heated and freezes to a Brittle, very Glassy state when cooled sufficiently A musical instrument is a device constructed or modified for the purpose of making Music. The violin is a bowed String instrument with four strings usually tuned in Perfect fifths It is the smallest and highest-pitched member The guitar is a Musical instrument with ancient roots that is used in a wide variety of musical styles In Chemistry, chemical synthesis is purposeful execution of Chemical reactions in order to get a product, or several products Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products Animal sinews and skins, including leather, have been used to make useful articles for millennia. Leather is a material created through the Tanning of hides and Skins of Animals primarily Cattlehide The Tanning process

Gelatin-resorcinol-formaldehyde glue (and with formaldehyde replaced by less-toxic pentanedial and ethanedial) has been used to repair experimental incisions in rabbit lungs. Resorcinol (or resorcin) is a Chemical compound from the dihydroxy Phenols it is the 13- Isomer of Benzenediol. Formaldehyde is a Chemical compound with the formula H2CO It is the simplest Aldehyde —an organic compound containing a terminal Carbonyl Glyoxal is an Organic compound with the formula OCHCHO This yellow-coloured liquid is the smallest Dialdehyde (two Aldehyde groups Rabbits are small Mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world lung is the essential Respiration organ in air-breathing Animals including most Tetrapods a few Fish and a few Snails The most primitive [4]

Medical uses

Collagen has been widely used in cosmetic surgery, as a healing aid for burn patients for reconstruction of bone and a wide variety of dental, orthopedic and surgical purposes. Some points of interest are:

  1. when used cosmetically, there is a chance of allergic reactions causing prolonged redness; however, this can be virtually eliminated by simple and inconspicuous patch testing prior to cosmetic use, and
  2. most medical collagen is derived from young beef cattle (bovine) from certified BSE (Bovine spongiform encephalopathy) free animals. Bovine Spongiform Encephalopathy ( BSE) commonly known as Mad-Cow Disease ( MCD) is a fatal Neurodegenerative disease in Cattle Most manufacturers use donor animals from either "closed herds", or from countries which have never had a reported case of BSE such as Australia and New Zealand.
  3. porcine (pig) tissue is also widely used for producing collagen sheet for a variety of surgical purposes.
  4. due to the care in donor animal breeding and selection, as well as the technology used in the preparation of collagen from animal sources, the chance of immune reactions or disease transmission has been virtually eliminated.
  5. alternatives using the patient's own fat, hyaluronic acid or polyacrylamide gel are readily available. Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water Hyaluronan (also called hyaluronic acid or hyaluronate) is a non-sulfated Glycosaminoglycan distributed widely throughout connective, epithelial

Collagens are widely employed in the construction of artificial skin substitutes used in the management of severe burns. A burn is a type of Injury that may be caused by Heat, cold, Electricity, Chemicals, Light, Radiation, or These collagens may be derived from bovine, equine or porcine, and even human, sources and are sometimes used in combination with silicones, glycosaminoglycans, fibroblasts, growth factors and other substances. Silicones are largely inert compounds with a wide variety of forms and uses Glycosaminoglycans (GAGs or mucopolysaccharides are long unbranched Polysaccharides consisting of a repeating Disaccharide unit A fibroblast is a type of cell that synthesizes and maintains the Extracellular matrix of many Animal tissues The term growth factor refers to a naturally occurring Protein capable of stimulating cellular growth proliferation and Cellular differentiation.

Collagen is also sold commercially as a joint mobility supplement. This lacks supportive research as the proteins would just be broken down into its base amino acids during digestion, and could go to a variety of places besides the joints depending upon need and DNA orders.

Recently an alternative to animal-derived collagen has become available. Although expensive, this human collagen, derived from donor cadavers, placentas and aborted fetuses, may minimize the possibility of immune reactions. The placenta is an Ephemeral organ present in placental Vertebrates, such as Eutherial Mammals and Sharks during Gestation

Collagen is now being used as a main ingredient for some cosmetic makeup.

Composition and structure

The structure of collagen eluded scientists for decades. Many prominent scholars, including Nobel laureates like Watson and Crick and Linus Pauling were known to have been working on collagen structure when it was finally discovered. [5] The triple helical structure that is known to be correct in the essentials was proposed by G. N. Ramachandran and Gopinath Kartha in the year 1954. [6][7] This proposed structure came to be known as the Madras helix.

The tropocollagen or "collagen molecule" subunit is a rod about 300 nm long and 1. 5 nm in diameter, made up of three polypeptide strands, each of which is a left-handed helix, not to be confused with the commonly occurring alpha helix, which is right-handed. Peptides (from the Greek πεπτίδια, "small digestibles" are short Polymers formed from the linking in a defined order of α- Amino A helix (pl helixes or helices) from the Greek word έλιξ, is a special kind of Space curve, i These three left-handed helices are twisted together into a right-handed coiled coil, a triple helix or "super helix", a cooperative quaternary structure stabilized by numerous hydrogen bonds. For the coiled coil shape in general see Coil. A coiled coil is a Structural motif in Proteins in which 2-7 In Biochemistry, quaternary structure is the arrangement of multiple folded Protein molecules in a multi-subunit complex A hydrogen bond results from a Dipole-dipole force between an Electronegative atom and a Hydrogen atom bonded to Nitrogen, Oxygen Tropocollagen subunits spontaneously self-assemble, with regularly staggered ends, into even larger arrays in the extracellular spaces of tissues. In Structural biology, a protein subunit or subunit protein is a single Protein Molecule that assembles (or " coassembles " Molecular self-assembly is the process by which Molecules adopt a defined arrangement without guidance or management from an outside source In Cell biology, Molecular biology and related fields the word extracellular (or sometimes extracellular space) means "outside the cell There is some covalent crosslinking within the triple helices, and a variable amount of covalent crosslinking between tropocollagen helices, to form the different types of collagen found in different mature tissues — similar to the situation found with the α-keratins in hair. Keratins are a family of fibrous structural proteins; tough and insoluble they form the hard but nonmineralized structures found in Reptiles Birds Hair is a keratinised protein filament that grows through the epidermis from follicles deep within the Dermis. Collagen's insolubility was a barrier to study until it was found that tropocollagen from young animals can be extracted because it is not yet fully crosslinked. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Cross-links are bonds that link one Polymer chain to another They can be Covalent bonds or Ionic bonds "Polymer chains" can refer

Collagen fibrils are collagen molecules packed into an organized overlapping bundle. Collagen fibers are bundles of fibrils.

A distinctive feature of collagen is the regular arrangement of amino acids in each of the three chains of these collagen subunits. The sequence often follows the pattern Gly-Pro-Y or Gly-X-Hyp, where X and Y may be any of various other amino acid residues. Glycine (abbreviated as Gly or G) is the Organic compound with the formula NH2CH2COOH Proline (abbreviated as Pro or P) is an α- Amino acid, one of the twenty DNA -encoded amino acids 4-Hydroxyproline, or hydroxyproline ( C 5 H 9 O 3 N) is an uncommon Amino acid, abbreviated as HYP Gly-Pro-Hyp occurs frequently. This kind of regular repetition and high glycine content is found in only a few other fibrous proteins, such as silk fibroin. Silk is a natural Protein Fiber, some forms of which can be woven into Textiles The best-known type of silk is obtained from cocoons Fibroin is a type of protein created by Bombyx mori (silkworms in the production of Silk. 75-80% of silk is (approximately) -Gly-Ala-Gly-Ala- with 10% serine — and elastin is rich in glycine, proline, and alanine (Ala), whose side group is a small, inert methyl group. Serine (abbreviated as Ser or S) is an Organic compound with the formula H[[oxygen O]]2 CCH NH sub>2CH2OH Elastin is a Protein in Connective tissue that is elastic and allows many tissues in the body to resume their shape after stretching or contracting A side chain in Organic chemistry and Biochemistry is a part of a Molecule that is attached to a core structure In Chemistry, a methyl group is a Hydrophobic Alkyl Functional group named after Methane (4 Such high glycine and regular repetitions are never found in globular proteins. Chemically-reactive side groups are not needed in structural proteins as they are in enzymes and transport proteins. A chemical reaction is a process that always results in the interconversion of Chemical substances The substance or substances initially involved in a chemical reaction are called The high content of Proline and Hydroxyproline rings, with their geometrically constrained carboxyl and (secondary) amino groups, accounts for the tendency of the individual polypeptide strands to form left-handed helices spontaneously, without any intrachain hydrogen bonding. Carboxyl group or CO2H is a Functional group present in Amino acids and Carboxylic acids Its structure is composed of one carbon atom attached Amines are Organic compounds and Functional groups that contain a basic Nitrogen Atom with a Lone pair.

Because glycine is the smallest amino acid, it plays a unique role in fibrous structural proteins. In collagen, Gly is required at every third position because the assembly of the triple helix puts this residue at the interior (axis) of the helix, where there is no space for a larger side group than glycine’s single hydrogen atom. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 History See also Atomic theory, Atomism The concept that matter is composed of discrete units and cannot be divided into arbitrarily tiny For the same reason, the rings of the Pro and Hyp must point outward. These two amino acids thermally stabilize the triple helix — Hyp even more so than Pro — and less of them is required in animals such as fish, whose body temperatures are low. Fish are aquatic Vertebrate animals that are typically ectothermic (previously Cold-blooded) covered with scales, and equipped with two Thermoregulation is the ability of an Organism to keep its body temperature within certain boundaries even when temperature surrounding is very different

In bone, entire collagen triple helices lie in a parallel, staggered array. 40 nm gaps between the ends of the tropocollagen subunits probably serve as nucleation sites for the deposition of long, hard, fine crystals of the mineral component, which is (approximately) hydroxyapatite, Ca10(PO4)6 (OH)2with some phosphate. Hydroxylapatite, also called hydroxyapatite, is a Mineral. It is a naturally occurring form of calcium Apatite with the formula Ca5(PO43(OH A phosphate, an Inorganic chemical, is a salt of Phosphoric acid. It is in this way that certain kinds of cartilage turn into bone. Collagen gives bone its elasticity and contributes to fracture resistance. A bone fracture (sometimes abbreviated # or Fx or Fx) is a medical condition in which a Bone is cracked or broken

Types and associated disorders

Collagen occurs in many places throughout the body. There are 28 types of collagen described in literature. Over 90% of the collagen in the body, however, are of type I, II, III, and IV. A simple way to remember their general functions is:

Collagen diseases commonly arise from genetic defects that affect the biosynthesis, assembly, postranslational modification, secretion, or other processes in the normal production of collagen.

Type Notes Gene(s) Disorders
I This is the most abundant collagen of the human body. Collagen disease is a term previously used to describe Systemic autoimmune diseases (e Type-I collagen is the most abundant collagen of the human body It is present in scar tissue, the end product when tissue heals by repair. Scars (also called cicatrices) are areas of fibrous tissue that replace normal Skin (or other tissue after injury Healing, assessed physically is the process by which the cells in the Body regenerate and repair to reduce the size of a damaged or necrotic area It is found in tendons, skin, artery walls, the endomysium of myofibrils, fibrocartilage, and the organic part of bones and teeth. A tendon (or sinew) is a tough band of Fibrous connective tissue that usually connects Muscle to Bone and is capable of withstanding tension The endomysium, literally meaning within the muscle is a layer of connective tissue that ensheaths a muscle fiber and is composed mostly from reticular fibers COL1A1, COL1A2 osteogenesis imperfecta, Ehlers-Danlos Syndrome
II Hyaline cartilage, makes up 50% of all cartilage protein. Osteogenesis imperfecta ( OI and sometimes known as Brittle Bone Disease) is a genetic bone disorder Ehlers-Danlos syndrome is a group of rare Genetic disorders affecting humans caused by a defect in Collagen synthesis Type-II collagen is the basis for Articular cartilage and Hyaline cartilage. Hyaline cartilage (aka “Gristle" consists of a slimy mass of a firm consistency but of considerable elasticity and pearly bluish color Vitreous humour of the eye. Fibrocartilage. COL2A1 Collagenopathy, types II and XI
III This is the collagen of granulation tissue, and is produced quickly by young fibroblasts before the tougher type I collagen is synthesized. The type II and XI collagenopathies are a group of disorders that affect Connective tissue, the tissue that supports the body's joints and organs Collagen type III alpha 1 (Ehlers-Danlos syndrome type IV autosomal dominant, also known as COL3A1, is a human Gene. Granulation tissue is the perfused, fibrous connective tissue that replaces a Fibrin clot in healing wounds. Reticular fiber. Reticular fibers or reticulin is a histological term used to describe a type of Structural fiber composed of Type III collagen. Also found in artery walls, skin, intestines and the uterus COL3A1 Ehlers-Danlos Syndrome
IV basal lamina; eye lens. Ehlers-Danlos syndrome is a group of rare Genetic disorders affecting humans caused by a defect in Collagen synthesis Type-IV collagen is a type of Collagen found primarily in the Basal lamina. The basal lamina is a layer of extracellular matrix on which Epithelium sits and which is secreted by the epithelial cells The lens is a transparent biconvex structure in the Eye that along with the Cornea, helps to Refract Light to be focused Also serves as part of the filtration system in capillaries and the glomeruli of nephron in the kidney. Capillaries are the smallest of a body's Blood vessels measuring 5-10 μm in diameter which connect Arterioles and Venules and enable the interchange A glomerulus is a Capillary tuft surrounded by Bowman's capsule in Nephrons of the vertebrate Kidney. A nephron (from Greek νεφρός (nephros meaning "kidney" is the basic structural and functional unit of the Kidney. The kidneys are complicated organs that have numerous biological roles COL4A1, COL4A2, COL4A3, COL4A4, COL4A5, COL4A6 Alport syndrome
V most interstitial tissue, assoc. Collagen type IV alpha 5 (Alport syndrome, also known as COL4A5, is a human Gene. Alport syndrome is a Genetic disorder characterized by Glomerulonephritis, endstage kidney disease and hearing loss with type I, associated with placenta COL5A1, COL5A2, COL5A3 Ehlers-Danlos syndrome (Classical)
VI most interstitial tissue, assoc. The placenta is an Ephemeral organ present in placental Vertebrates, such as Eutherial Mammals and Sharks during Gestation Ehlers-Danlos syndrome is a group of rare Genetic disorders affecting humans caused by a defect in Collagen synthesis with type I COL6A1, COL6A2, COL6A3 Ulrich myopathy and Bethlem myopathy
VII forms anchoring fibrils in dermal epidermal junctions COL7A1 epidermolysis bullosa
VIII some endothelial cells COL8A1, COL8A2 -
IX FACIT collagen, cartilage, assoc. Bethlem myopathy is an Autosomal Dominant Myopathy, classified as a Congenital form of Muscular dystrophy Anchoring fibrils (composed largely of type VII Collagen) extend from the Basal lamina of Epithelial cells and attach to the lamina reticularis (also known The dermis is a layer of Skin beneath the epidermis that consists of Connective tissue, and cushions the body from stress and strain A cell junction is a structure within a tissue of a Multicellular Organism. Collagen type VII alpha 1 (epidermolysis bullosa dystrophic dominant and recessive, also known as COL7A1, is a human Gene. Epidermolysis Bullosa ( EB) is a rare Genetic disease characterized by the presence of extremely fragile Skin and recurrent Blister FACIT collagen ( Fibril Associated Collagens with Interrupted Triple helices) refers to a type of Collagen which is also a Proteoglycan. with type II and XI fibrils COL9A1, COL9A2, COL9A3 - EDM2 and EDM3
X hypertrophic and mineralizing cartilage COL10A1 -
XI cartilage COL11A1, COL11A2 Collagenopathy, types II and XI
XII FACIT collagen, interacts with type I containing fibrils, decorin and glycosaminoglycans COL12A1 -
XIII transmembrane collagen, interacts with integrin a1b1, fibronectin and components of basement membranes like nidogen and perlecan. The type II and XI collagenopathies are a group of disorders that affect Connective tissue, the tissue that supports the body's joints and organs FACIT collagen ( Fibril Associated Collagens with Interrupted Triple helices) refers to a type of Collagen which is also a Proteoglycan. Decorin is a Proteoglycan on average 90 - 140 Fibronectin is a high-molecular-weight extracellular matrix Glycoprotein containing about 5% Carbohydrate that binds to membrane spanning Receptor proteins Entactin (or nidogen) is a component of the Basement membrane alongside other components such as Collagen type IV Proteoglycans ( heparan sulfate Heparan sulfate proteoglycan 2 ( HSPG2) is a human Gene which encodes the perlecan Protein. COL13A1 -
XIV FACIT collagen COL14A1 -
XV - COL15A1 -
XVI - COL16A1 -
XVII transmembrane collagen, also known as BP180, a 180 kDa protein COL17A1 Bullous Pemphigoid and certain forms of junctional epidermolysis bullosa
XVIII source of endostatin COL18A1 -
XIX FACIT collagen COL19A1 -
XX - COL20A1 -
XXI FACIT collagen COL21A1 -
XXII - COL22A1 -
XXIII - COL23A1 -
XXIV - COL24A1 -
XXV - COL25A1 -
XXVI - EMID2 -
XXVII - COL27A1 -
XXVIII - COL28A1 -

In addition to the above mentioned disorders, excessive deposition of collagen occurs in Scleroderma. FACIT collagen ( Fibril Associated Collagens with Interrupted Triple helices) refers to a type of Collagen which is also a Proteoglycan. Collagen XVII, previously called BP180 is a transmembrane protein which plays a critical role in maintaining the linkage between the intracellular and the extracellular structural elements Bullous pemphigoid, also referred to as BP, is a chronic autoimmune Skin disease, involving the formation of Blisters below the surface of the Epidermolysis Bullosa ( EB) is a rare Genetic disease characterized by the presence of extremely fragile Skin and recurrent Blister Type XVIII collagen is a type of Collagen which can be cleaved to form Endostatin. Endostatin is a naturally-occurring 20-kDa C-terminal fragment derived from Type XVIII collagen. Collagen type XVIII alpha 1, also known as COL18A1, is a human Gene. FACIT collagen ( Fibril Associated Collagens with Interrupted Triple helices) refers to a type of Collagen which is also a Proteoglycan. FACIT collagen ( Fibril Associated Collagens with Interrupted Triple helices) refers to a type of Collagen which is also a Proteoglycan. Scleroderma is a chronic Autoimmune disease characterized by a hardening or Sclerosis in the Skin or other organs

Staining

In histology, collagen is brightly eosinophilic (pink) in standard H&E slides. Histology (from the Greek = 'tissue' is the study of the microscopic anatomy of cells and tissues of Plants and H&E stain, HE stain or hematoxylin and eosin stain, is a popular Staining method in Histology. The dye methyl violet may be used to stain the collagen in tissue samples. A dye can generally be described as a Colored substance that has an affinity to the substrate to which it is being applied Methyl violet is the name given to a group of similar Chemicals used as PH indicators and Dyes Methyl violets are mixtures of tetramethyl pentamethyl and Staining is an auxiliary Technique used in Microscopy to enhance contrast in the microscopic image

The dye methyl blue can also be used to stain collagen and immunohistochemical stains are available if required. Methyl blue, also known as Cotton blue, Helvetia blue, Acid blue 93, or C Immunohistochemistry or IHC refers to the process of localizing proteins in cells of a tissue section exploiting the principle of antibodies binding specifically

The best stain for use in differentiating collagen from other fibers is Masson's trichrome stain. Masson's trichrome is a three-color staining protocol used in Histology.

Synthesis

Amino acids

Collagen has an unusual amino acid composition and sequence:

Collagen I formation

Most collagen forms in a similar manner, but the following process is typical for type I:

  1. Inside the cell
    1. Three peptide chains are formed (2 alpha-1 and 1 alpha-2 chain) in ribosomes along the Rough Endoplasmic Reticulum (RER). Peptides (from the Greek πεπτίδια, "small digestibles" are short Polymers formed from the linking in a defined order of α- Amino The endoplasmic reticulum (Greek endo = "within" (prefix plásma = "formed entity" Latin reticulum = "little net" or ER, is an Organelle These peptide chains (known as preprocollagen) have registration peptides on each end; and a signal peptide is also attached to each
    2. Peptide chains are sent into the lumen of the RER
    3. Signal Peptides are cleaved inside the RER and the chains are now known as procollagen
    4. Hydroxylation of lysine and proline amino acids occurs inside the lumen. A signal peptide is a short (3-60 Amino acids long Peptide chain that directs the post- translational transport of a Protein. Hydroxylation is any chemical process that introduces one or more hydroxyl groups (-OH into a compound (or radical thereby oxidizing it Lysine (abbreviated as Lys or K) is an α- Amino acid with the Chemical formula HO2CCH(NH2(CH24NH2 Proline (abbreviated as Pro or P) is an α- Amino acid, one of the twenty DNA -encoded amino acids This process is dependent on Ascorbic Acid (Vitamin C) as a cofactor
    5. Glycosylation of specific hydroxylated amino acid occurs
    6. Triple helical structure is formed inside the RER
    7. Procollagen is shipped to the golgi apparatus, where it is packaged and secreted by exocytosis
  2. Outside the cell
    1. Registration peptides are cleaved and tropocollagen is formed by procollagen peptidase. This article deals with the molecular aspects of ascorbic acid Glycosylation is the enzymatic process that links Saccharides to produce glycans, either free or attached to Proteins and Lipids This enzymatic Collagen is the main Protein of Connective tissue in Animals and the most abundant protein in Mammals making up about 50% of the whole-body protein The Golgi apparatus (also called the Exocytosis (ek-soh-sy-TOH-sis Greek: Έξω - external and κύτος - cell is the durable process by which a cell directs secretory vesicles out of the Cell Procollagen peptidase is an Endopeptidase involved in the processing of Collagen.
    2. Multiple tropocollagen molecules form collagen fibrils, and multiple collagen fibrils form into collagen fibers
    3. Collagen is attached to cell membranes via several types of protein, including fibronectin and integrin. Fibronectin is a high-molecular-weight extracellular matrix Glycoprotein containing about 5% Carbohydrate that binds to membrane spanning Receptor proteins Integrins are Cell surface receptors that interact with the Extracellular matrix (ECM and mediate various intracellular signals.

Synthetic pathogenesis

Vitamin C deficiency causes scurvy, a serious and painful disease in which defective collagen prevents the formation of strong connective tissue. Scurvy (NLat scorbutus is a disease resulting from a deficiency of Vitamin C, which is required for the synthesis of Collagen in humans A disease is an abnormal condition of an organism that impairs bodily functions and can be deadly Connective tissue is one of the four types of tissue in traditional classifications (the others being epithelial, Muscle, and Nervous tissue) Gums deteriorate and bleed, with loss of teeth; skin discolors, and wounds do not heal. The gingiva (sing and plur: gingiva) or gums, consists of the Mucosal tissue that lies over the Alveolar bone. In Medicine, a wound is a type of Injury in which the Skin is torn cut or punctured (an open wound or where blunt force trauma Prior to the eighteenth century, this condition was notorious among long duration military, particularly naval, expeditions during which participants were deprived of foods containing Vitamin C. In the human body, a malfunction of the immune system, called an autoimmune disease, results in an immune response in which healthy collagen fibers are systematically destroyed with inflammation of surrounding tissues. An immune system is a collection of mechanisms within an Organism that protects against Disease by identifying and killing Pathogens and Tumor Autoimmune diseases arise from an overactive Immune response of the body against substances and tissues normally present in the body The resulting disease processes are called Lupus erythematosus, and rheumatoid arthritis, or collagen tissue disorders. Systemic lupus erythematosus ( SLE or lupus,) is a chronic autoimmune disease that can be fatal though with recent medical advances fatalities are becoming Rheumatoid arthritis ( RA) is a chronic systemic autoimmune disorder that causes the Immune system to attack the Joints, where [8]

Many bacteria and viruses have virulence factors which destroy collagen or interfere with its production.

Art

Julian Voss-Andreae's sculpture Unraveling Collagen (2005), stainless steel, height 11'3" (3.40 m).
Julian Voss-Andreae's sculpture Unraveling Collagen (2005), stainless steel, height 11'3" (3. 40 m).

Julian Voss-Andreae has created sculptures based on the collagen structure out of bamboo and stainless steel. His piece "Unraveling Collagen" is, according to the artist, a "metaphor for aging and growth"[9][10].

See also

References

  1. ^ Gloria A. Osteoid is the organic portion of the matrix of bone tissue. Osteoblasts begin the process of forming bone tissue by secreting the osteoid as several specific Fibrous proteins, also called scleroproteins, are one of the two main classes of protein Quaternary structure (the other being Globular proteins. Ehlers-Danlos syndrome is a group of rare Genetic disorders affecting humans caused by a defect in Collagen synthesis Di LulloDagger , Shawn M. Sweeney, Jarmo Körkkö, Leena Ala-Kokko, and James D. San Antonio; Mapping the Ligand-binding Sites and Disease-associated Mutations on the Most Abundant Protein in the Human, Type I Collagen; J. Biol. Chem. , Vol. 277, Issue 6, 4223-4231, February 8, 2002
  2. ^ Gelatin's Advantages: Health, Nutrition and Safety
  3. ^ Oldest Glue Discovered
  4. ^ Ann Thorac Surg. 1994 Jun; 57(6): 1622-7
  5. ^ GNR — A Tribute - Resonance - October 2001
  6. ^ http://www.proteinscience.org/cgi/reprint/10/8/1689.pdf
  7. ^ G.N. Ramachandran - Nature Structural & Molecular Biology
  8. ^ AJR article about lupus and other collagen disorders
  9. ^ Ward, Barbara (April 2006). "'Unraveling Collagen' structure to be installed in Orange Memorial Park Sculpture Garden". Expert Rev. Proteomics 3 (2): 174. doi:10.1586/14789450.3.2.169. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.  
  10. ^ Interview with J. Voss-Andreae "Seeing Below the Surface" in Seed Magazine

Additional images

Collagen

Action of lysyl oxydase (in French)

External links


Dictionary

collagen

-noun

  1. (biochemistry) Any of more than 28 types of glycoprotein that forms elongated fibers, usually found in the extracellular matrix of connective tissue.
© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
 Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic