| 摘要 |
PURPOSE:To enable easy production of a large amount of L-cysteine and/or L-cystine, by reacting a beta-substituted L-alanine with a specific compound such as metal sulfide in the presence of a tryptophan synthase. CONSTITUTION:A beta-substituted L-alanine of formula [X is a halogen, -OR or -SR (R is H, alkyl, acetyl, benzyl or sulfonic acid group)] is made to react with a metal sulfide, metal hydrosulfide, metal polysulfide, ammonium sulfide, ammonium hydrosulfide or ammonium polysulfide in the presence of a tryptophan synthase preferably in an aqueous medium at 6-10pH and 20-60 deg.C. The tryptophan synthase can be separated e.g. from cultured cell of Escherichia coli MT-10232 (FERM BP-19). |
