Sulfur Uptake by Type I Collagen from Methyl Mercaptan/Dimethyl Disulfide Air Mixtures

Abstract

Type I acid-soluble collagen, suspended in 0.02 M Tris/0.13 M NaCl buffer (pH 7.4), was exposed to air atmosphere admixed with 10.7 × 10^-9 moles of [ ³⁵ S]-labeled dimethyl disulphidelmethyl mercaptan mixture in the ratio of 99.82% (CH ₃ S) ₂ /0.18% CH3SH. Gas chromatographic analyses of head-space following one and four days of incubation indicated that all of the CH ₃ SH was absorbed from the head-space by the collagen-containing liquid phase, while the (CH ₃ S) ₂ concentration of the head-space remained essentially unchanged. Of the total [ ³⁵ S]-activity initially present in the head-space, only 1.0 and 1.86% was absorbed by the collagen-containing liquid phase within one and four days, respectively. Paper chromatographic separation of the reaction mixture showed that only 0.42 and 0.60% of the radioactivity in the head-space was associated with collagen after one and four days of reaction.

In comparable [ ³⁵ SJ-H ₂ S systems devoid of (CH ₃ S) ₂ , all of the H ₂ S was absorbed within 48 hours of incubation with 18.04% (1 day) and 18.28% (4 days) of the available [ ³⁵ S]-H ₂ S complexed with collagen. The results provide evidence that the reaction of collagen with H ₂ S and CH ₃ SH/(CH ₃ S) ₂ mixture proceeded via the H ₂ S and CH3SH thiol groups.