Biochemical and photometric studies of modification of collagen structure induced by UV irradiation

The influence of UV irradiation (270–380 nm) on the biochemical, fluorescence and colorimetric properties of collagen was studied. The long-term UV irradiation (120 h) was accompanied by the increase of the structural stability of collagen to specific and nonspecific proteolytic enzymes, by formation of new additional fluorophore containing compounds, by the increased amount of carbonyl groups in the collagen, and by significant changes in the distribution pattern of products of alkaline hydrolysis during gel chromatography. The coordinates of color of the collagen films have been also changed. These changes of collagen suggest that UV irradiation induces photomodification and photooxidation processes in collagen.