ENZYMATIC PROOF FOR THE IDENTITY OF THE S-SULFOCYSTEINE SYNTHASE AND CYSTEINE SYNTHASE-B OF SALMONELLA-TYPHIMURIUM
ENZYMATIC PROOF FOR THE IDENTITY OF THE S-SULFOCYSTEINE SYNTHASE AND CYSTEINE SYNTHASE-B OF SALMONELLA-TYPHIMURIUM
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DOI：
10.1128/jb.158.3.1122-1127.1984
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发表时间：
1984-01-01
影响因子：
3.2
通讯作者：
EGUCHI, Y
中科院分区：
文献类型：
--
作者：
NAKAMURA, T;IWAHASHI, H;EGUCHI, Y
通过聚丙烯酰胺凝胶电泳从鼠伤寒沙门氏菌 LT-2 中分离出 S-磺基半胱氨酸合酶，使其呈均质形式。该酶的MW被确定为.apprx。 55,000。该酶由 2 个大小相同的亚基组成，每个亚基含有 1 个磷酸吡哆醛。除了从硫代硫酸盐和O-乙酰丝氨酸形成S-磺基半胱氨酸之外，该酶还分别催化从硫化物或甲硫醇和O-乙酰丝氨酸生物合成半胱氨酸或S-甲基半胱氨酸。 该酶与半胱氨酸合酶 B 相同。该酶的细胞内水平受到与半胱氨酸合酶 A 有效的相同因素的较小程度的调节。
S-Sulfocysteine synthase was isolated from S. typhimurium LT-2 to homogeneous form with polyacrylamide gel electrophoresis. The MW of this enzyme was determined to be .apprx. 55,000. The enzyme consisted of 2 identically sized subunits, and it contained 1 pyridoxal phosphate/subunit. The enzyme catalyzed the biosynthesis of cysteine or S-methylcysteine from sulfide or methanethiol and O-acetylserine, respectively, in addition to the formation of S-sulfocysteine from thiosulfate and O-acetylserine. The enzyme is identical to cysteine synthase B. The intracellular level of this enzyme was regulated by lesser extents of the same factors as those effective for cysteine synthase A.