PROTEIN METABOLISM IN REGENERATING WOUND TISSUE: FUNCTION OF THE SULFUR AMINO ACIDS.

Studies on the rate of incorporation of sulfur amino acids into regenerating wound tissue have been carried out. By appropriate rate studies, the putative incorporation of L-methionine-S35 into collagen may be distinguished from that into the metabolically active proteins. The utilization of methionine by the latter follows a pattern which is quite analogous to that shown for incorporation of L-cystine-S35. Whether the labeled cystine incorporated into the wound tissue arises from L-methionine-S35 or is administered in the form of L-cystine-S35, it is possible to differentiate two types of cystine-containing proteins one, which is synthesized and turned over comparatively rapidly and the other which is formed more slowly and is more stable. Considering the time and rate of formation of the rapidly formed cystine-containing protein, a tentative connection with the mechanism involved in the deposition of collagen in wound tissue is postulated. Changes in systemic sulfur metabolism were also observed during course of these experiments. Author