Chemical changes associated with aging of collagen in vivo and in vitro.
Collagen extracted from rat skin by neutral-salt solutions contains less aldehydes than the more insoluble collagen fractions. The concentration of aldehydes in collagen is directly related to its capacity to form stable cross-linked gels, which do not redissolve on cooling and become more insoluble in a variety of reagents. Whereas the absorption spectrum of neutral-salt-soluble collagen treated with N-methylbenzothiazolone hydrazone resembles that of acetaldehyde, the more insoluble collagen fractions show increasing amounts of a component that behaves like an alphabeta-unsaturated aldehyde. The ratio between alpha- and beta-sub-units present in a particular fraction of soluble collagen seems to be constant and independent of the age of the animal. Neutral-salt-soluble collagen, which has a low concentration of beta-components, will generate intramolecular bonds if gelled at 37 degrees . These intramolecular bonds seem to precede the formation of stable intermolecular cross-links, since these gels can redissolve when cooled to yield a soluble collagen with a higher content of beta-components of intramolecular origin.
D000085:Acetates; D000367:Age Factors; D000447:Aldehydes / Q000032:analysis; D000818:Animals; D055598:Chemical Phenomena; D011232:Chemical Precipitation; D002621:Chemistry; D003094:Collagen / Q000032:analysis; D003543:Cysteamine; D003720:Densitometry; D004355:Drug Stability; D004589:Electrophoresis, Disc; D005782:Gels; D008297:Male; D011489:Protein Denaturation; D051381:Rats; D012867:Skin; D012995:Solubility; D013053:Spectrophotometry; D013696:Temperature; D013844:Thiazoles; D013997:Time Factors
D000085:Acetates; D000447:Aldehydes; D005782:Gels; D013844:Thiazoles; D003543:Cysteamine; D003094:Collagen