The relationship between the degree of hydroxylation and oxidative deamination of e-NH2-groups of lysine and hydroxylysine in collagen, and the thermal stability of this protein’s sub-molecular structures in the skin of Wistar rats in their postnatal ontogeny was in vitro studied. It has been shown that, rising towards the age of 3 months, the content of free e-NH2-groups in collagen continuously remains constant, while that of free aldehyde groups (COH-groups), starting from 1-month steadily decreases with age. Accordingly, intermolecular cross-linking in collagen’s sub-molecular structures is reduced during the period between 1 to 3 months, and afterwards continuously increases up to 24 months of age. The content of hydroxyproline in collagen is continuously reduced in postnatal ontogenesis. The combined effect of both effects leads to a decrease in the thermal stability of collagen sub-molecular structures in the skin during the period from 1 to 3 months, and subsequently rises up to 24 months old.
El-ta'alu A B, Persky, Eu E, Bulankina Na I, Kot Yu G, Kot Ek V, Ponomarenko Al N, Kostina Ta V. The Role of Collagen Processing in Age-related Changes in the Thermo-stability of Connective Tissue Macromolecule - Collagen . WebmedCentral BIOCHEMISTRY 2011;2(11):WMC002392