Collagen is a glycoprotein containing galactose and glucose. Hydroxyproline is exclusive to collagen and due to this reason to estimate collagen normally hydroxyproline is estimation is done. Collagen has intermolecular cross linkages and due to these has high tensile strength of collagen fibers. Younger the animal lesser are the cross links. As the animal progresses in age the collagen cross-link concentration increases.
Oxidative deamination initiates the cross linking through lysyl oxidase.
Cross linking of collagen is a progressive process but it is not that it is in every muscle. There are about 14 types collagen. The type I, II, III comprise the bulk. Collagen type IV Found around different types of in the basement membranes and muscles. It is found in embryonic cell cultures and the basement membranes.