Age-related Differences in Human Skin Collagen: Solubility in Solvent, Susceptibility to Pepsin Digestion, and the Spectrum of the Solubilized Polymeric Collagen Molecules

Abstract

Age-related differences of human skin collagen in solubility, susceptibility to pepsin digestion, and the spectrum of collagen molecules were systematically examined. Less than .5% of the skin collagen were solubilized in a neutral salt solution. The solubility in acetic acid decreased rapidly during maturation and then slowly with age. Insoluble collagen from an infant was almost completely solubilized by pepsin digestion, whereas most of that from the elderly individuals remained insoluble even after four repeated times of pepsin digestion. The solubilized collagen was considered to contain a considerable amount of polymeric molecules. Characteristically, the amount of the Millipore-retained fraction of pepsin-solubilized collagen was prominent at the fourth decade. These differences represent the aging process of collagen.

Age‐related expression, enzymatic solubility and modification with advanced glycation end‐products of fibrillar collagens in mouse lung

“…Like posttranslational hydroxylations the AGE modification of collagen additionally reduces its turnover by impairing the proteolytic solubility of collagen (Avery and Bailey, 2005;Bartling et al, 2009;Brennan, 1989;Degroot et al, 2001;Reddy, 2004;Sajithlal et al, 1998;Salmela et al, 1989). In our study we detected an age-dependent reduction of the pepsin solubility of lung collagens, which had also been detected for human skin collagens (Miyahara et al, 1982). In contrast to collagens from human, macaque and dog (Hamlin et al, 1978(Hamlin et al, , 1980Verzijl et al, 2000a), the collagenase I-mediated solubility of our mouse lung collagens was less affected by age.…”

Increasing Thermal Stability of Gelatin by UV-Induced Cross-Linking with Glucose

“…Gelatin has many properties which make it an ideal starting material for cell scaffolds. Native gelatin is easily degraded by proteases, possesses minimal antigenicity [52, 53], and is very soluble in aqueous solution [54]. Based on our results, cross-linking gelatin renders it insoluble at physiological temperatures; prior work also correlates greater cross-linking density with reduced rate of enzymatic degradation [32].…”

Natural Polymers as Components of Blends for Biomedical Applications

“…Each collagen molecule undergoes a strong molecular connection with neighboring collagen molecules by hydrogen bonding and other crosslinks [63][64][65][67][68][69]. Highly crosslinked collagen is usually insoluble in water [70]. Additional crosslinking of collagen can be made by exposure of collagen to UV irradiation [71].…”