Collagen Type IX
A fibril-associated collagen usually found crosslinked to the surface of COLLAGEN TYPE II fibrils. It is a heterotrimer containing alpha1(IX), alpha2(IX) and alpha3(IX) subunits.
Collagen
Cartilage
A non-vascular form of connective tissue composed of CHONDROCYTES embedded in a matrix that includes CHONDROITIN SULFATE and various types of FIBRILLAR COLLAGEN. There are three major types: HYALINE CARTILAGE; FIBROCARTILAGE; and ELASTIC CARTILAGE.
Collagen Type I
The most common form of fibrillar collagen. It is a major constituent of bone (BONE AND BONES) and SKIN and consists of a heterotrimer of two alpha1(I) and one alpha2(I) chains.
Collagen Type III
A fibrillar collagen consisting of three identical alpha1(III) chains that is widely distributed in many tissues containing COLLAGEN TYPE I. It is particularly abundant in BLOOD VESSELS and may play a role in tissues with elastic characteristics.
Collagen Type IV
A non-fibrillar collagen found in the structure of BASEMENT MEMBRANE. Collagen type IV molecules assemble to form a sheet-like network which is involved in maintaining the structural integrity of basement membranes. The predominant form of the protein is comprised of two alpha1(IV) subunits and one alpha2(IV) subunit, however, at least six different alpha subunits can be incorporated into the heterotrimer.
Collagen Type II
Collagen Type XI
A fibrillar collagen found primarily in interstitial CARTILAGE. Collagen type XI is heterotrimer containing alpha1(XI), alpha2(XI) and alpha3(XI) subunits.
Collagen Type V
A fibrillar collagen found widely distributed as a minor component in tissues that contain COLLAGEN TYPE I and COLLAGEN TYPE III. It is a heterotrimeric molecule composed of alpha1(V), alpha2(V) and alpha3(V) subunits. Several forms of collagen type V exist depending upon the composition of the subunits that form the trimer.
Fibrillar Collagens
A family of structurally related collagens that form the characteristic collagen fibril bundles seen in CONNECTIVE TISSUE.
Collagen Type VI
A non-fibrillar collagen that forms a network of MICROFIBRILS within the EXTRACELLULAR MATRIX of CONNECTIVE TISSUE. The alpha subunits of collagen type VI assemble into antiparallel, overlapping dimers which then align to form tetramers.
Extracellular Matrix
Extracellular Matrix Proteins
Macromolecular organic compounds that contain carbon, hydrogen, oxygen, nitrogen, and usually, sulfur. These macromolecules (proteins) form an intricate meshwork in which cells are embedded to construct tissues. Variations in the relative types of macromolecules and their organization determine the type of extracellular matrix, each adapted to the functional requirements of the tissue. The two main classes of macromolecules that form the extracellular matrix are: glycosaminoglycans, usually linked to proteins (proteoglycans), and fibrous proteins (e.g., COLLAGEN; ELASTIN; FIBRONECTINS; and LAMININ).
Receptors, Collagen
Collagen receptors are cell surface receptors that modulate signal transduction between cells and the EXTRACELLULAR MATRIX. They are found in many cell types and are involved in the maintenance and regulation of cell shape and behavior, including PLATELET ACTIVATION and aggregation, through many different signaling pathways and differences in their affinities for collagen isoforms. Collagen receptors include discoidin domain receptors, INTEGRINS, and glycoprotein VI.
Chick Embryo
Pepsin A
Formed from pig pepsinogen by cleavage of one peptide bond. The enzyme is a single polypeptide chain and is inhibited by methyl 2-diaazoacetamidohexanoate. It cleaves peptides preferentially at the carbonyl linkages of phenylalanine or leucine and acts as the principal digestive enzyme of gastric juice.
Chondroitin Lyases
Enzymes which catalyze the elimination of delta-4,5-D-glucuronate residues from polysaccharides containing 1,4-beta-hexosaminyl and 1,3-beta-D-glucuronosyl or 1,3-alpha-L-iduronosyl linkages thereby bringing about depolymerization. EC 4.2.2.4 acts on chondroitin sulfate A and C as well as on dermatan sulfate and slowly on hyaluronate. EC 4.2.2.5 acts on chondroitin sulfate A and C.
Cartilage, Articular
A protective layer of firm, flexible cartilage over the articulating ends of bones. It provides a smooth surface for joint movement, protecting the ends of long bones from wear at points of contact.
Collagen Type XVIII
A non-fibrillar collagen found in BASEMENT MEMBRANE. The C-terminal end of the alpha1 chain of collagen type XVIII contains the ENDOSTATIN peptide, which can be released by proteolytic cleavage.
Procollagen
A biosynthetic precursor of collagen containing additional amino acid sequences at the amino-terminal and carboxyl-terminal ends of the polypeptide chains.
Cells, Cultured
Collagen Type X
A non-fibrillar collagen found primarily in terminally differentiated hypertrophic CHONDROCYTES. It is a homotrimer of three identical alpha1(X) subunits.
Matrilin Proteins
PROTEOGLYCANS-associated proteins that are major components of EXTRACELLULAR MATRIX of various tissues including CARTILAGE; and INTERVERTEBRAL DISC structures. They bind COLLAGEN fibers and contain protein domains that enable oligomer formation and interaction with other extracellular matrix proteins such as CARTILAGE OLIGOMERIC MATRIX PROTEIN.
Collagen Type XII
A fibril-associated collagen found in many tissues bearing high tensile stress, such as TENDONS and LIGAMENTS. It is comprised of a trimer of three identical alpha1(XII) chains.
Fibronectins
Glycoproteins found on the surfaces of cells, particularly in fibrillar structures. The proteins are lost or reduced when these cells undergo viral or chemical transformation. They are highly susceptible to proteolysis and are substrates for activated blood coagulation factor VIII. The forms present in plasma are called cold-insoluble globulins.
Chondrocytes
Polymorphic cells that form cartilage.
Hydroxyproline
A hydroxylated form of the imino acid proline. A deficiency in ASCORBIC ACID can result in impaired hydroxyproline formation.
Fibroblasts
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.