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 CH3 SH was absorbed from the head-space by the collagen-containing liquid phase, while the (CH3 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-H2 S systems devoid of (CH3 S)2 , all of the H2 S was absorbed within 48 hours of incubation with 18.04% (1 day) and 18.28% (4 days) of the available [35 S]-H2 S complexed with collagen. The results provide evidence that the reaction of collagen with H2 S and CH3 SH/(CH3 S)2 mixture proceeded via the H2 S and CH3SH thiol groups.