Abstract
Binding of thiol-type thiamine with S-S groups of natural protein through thiol-disulfide exchange reaction, was investigated. When native or denatured bovine serum albumin (BSA) were incubated with its 10-160 molar amounts of thiamine at pH 9,37℃ for 1〜24 hours, about 0.6〜3.5 moles of bound thiamine (disulfide type) per mole of BSA was detected. Reduction of BSA greatly reduced the complex formation, suggesting involvement of the protein S-S groups. In an anaerobic conditions, however, the bound thiamine was much decreased and it was suggested that the thiamine disulfide, produced by air oxidation, was concerned with the large amounts of bound thiamine above mentioned. Sephadex gel filtration of the anaerobically incubated reaction mixture, followed by determination of SH groups showed that about 0.3 S-S groups of BSA was reduced. From these results it was supposed that thiamine itself could react only in some definite extent with S-S groups of BSA.
