Changes induced by ultraviolet light in fluorescence of collagen in the presence of beta-carotene

The influence of UV radiation (253.7 nm) on collagen fluorescence in the ab sence, and presence, of p-carotene was investigated. It was found that UV r adiation of 253.7 nm causes irreversible destruction of tyrosyl and phenyla lanyl residues. The fluorescence of collagen (excitation at 275 nm, emissio n at 305 nm) decreased rapidly during irradiation and a new fluorescence la rge band at 400-500 nm formed under UV radiation. Smaller changes in the fl uorescence of collagen in the presence of p-carotene suggest that it makes collagen less sensitive to the action of UV radiation. (C) 1999 Elsevier Sc ience S.A. All rights reserved.