BIOSYNTHESIS OF PUROMYCIN BY STREPTOMYCES-ALBONIGER - CHARACTERIZATION OF PUROMYCIN N-ACETYLTRANSFERASE
BIOSYNTHESIS OF PUROMYCIN BY STREPTOMYCES-ALBONIGER - CHARACTERIZATION OF PUROMYCIN N-ACETYLTRANSFERASE
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DOI：
10.1021/bi00348a036
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发表时间：
1985-12-31
期刊：
影响因子：
2.9
通讯作者：
JIMENEZ, A
中科院分区：
文献类型：
--
作者：
VARA, J;PEREZGONZALEZ, JA;JIMENEZ, A
来自白色链霉菌的嘌呤霉素n -乙酰转移酶通过使其酪氨酸基部分的氨基位置乙酰化而使嘌呤霉素失活。该酶经deae -纤维素和Affigel Blue柱层析纯化，并进行了表征。经凝胶过滤，其Mr值为23000。除嘌呤霉素外，n -乙酰化酶还能使o -去甲基嘌呤霉素（一种抗生素的毒性前体）和嘌呤霉素类似物抗生素黄嘌呤蛋白（一种嘌呤霉素类似物）乙酰化。puromycin和o -去甲基puromycin的Km值分别为1.7和4.6。M,分别。来自S. alboniger的o -去甲基嘌呤霉素o -甲基转移酶，它催化了嘌呤霉素生物合成的最后一步[Rao， M. M., Rebello， P.F., and Pogell， B.M.(1969)]。化学，244,112 -118],O-methylates N-acetyl-O-demethylpuromycin。o -去甲基嘌呤霉素和n -乙酰- o -去甲基嘌呤霉素的甲基化酶Km值分别为260和2.3 .mu。M,分别。这些发现表明，如果o -去甲基嘌呤霉素存在于白斑葡萄球菌中，它将被n -乙酰化，然后被o -甲基化转化为n -乙酰嘌呤霉素。甚至可能在更早的前体中发生嘌呤霉素骨架的n -乙酰化。
Puromycin N-acetyltransferase from Streptomyces alboniger inactivates puromycin by acetylating the amino position of its tyrosinyl moiety. This enzyme has been partially purified by column chromatography through DEAE-cellulose and Affigel Blue and characterized. It has an Mr of 23000, as determined by gel filtration. In addition to puromycin, the enzyme N-acetylates O-demethylpuromycin, a toxic precursor of the antibiotic, and chryscandin, a puromycin analogue antibiotic. The Km values for puromycin and O-demethylpuromycin are 1.7 and 4.6 .mu.M, respectively. The O-demethylpuromycin O-methyltransferase from S. alboniger, which apparently catalyzes the last step in the biosynthesis of puromycin [Rao, M. M., Rebello, P.F., and Pogell, B.M. (1969) J. Biol. Chem. 244, 112-118], also O-methylates N-acetyl-O-demethylpuromycin. The Km values of the methylating enzyme for O-demethylpuromycin and N-acetyl-O-demethylpuromycin are 260 and 2.3 .mu.M, respectively. These findings suggest that O-demethylpuromycin, if present in S. alboniger, would be N-acetylated and then O-methylated to be converted into N-acetylpuromycin. It might even be possible that N-acetylation of the puromycin backbone takes places at an earlier precursor.