ENZYMATIC STUDIES ON POLYKETIDE HYPOTHESIS
ENZYMATIC STUDIES ON POLYKETIDE HYPOTHESIS
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DOI：
10.1021/jf60168a008
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发表时间：
1970-01-01
影响因子：
6.1
通讯作者：
LIGHT, RJ
中科院分区：
文献类型：
--
作者：
LIGHT, RJ
聚酮假说提出许多天然产物是通过聚-1，8-羰基（聚酮）酸的环化生物合成得到的。这一假说的最新版本提出，聚酮酸链可以通过一个乙酰基和几个丙二酰硫醇酯以类似于脂肪酸生物合成的缩合反应的方式缩合形成。本文综述了支持这一假说的三种合成酶的性质：6-甲基水杨酸（6-MSA）合成酶、交链孢酚合成酶和地衣酸合成酶。6-MSA合成酶已被纯化约100倍，并已被证明是一个多酶复合物。研究聚酮酶的主要问题包括酶制剂的不稳定性和难以重复获得具有活性酶的培养物。6-MSA合成酶已被丙酮沉淀所稳定，并且该酶在培养物中的活性可被低浓度的放线菌酮所增强。
The polyketide hypothesis proposes that many natural products are derived biosynthetically by cyclization of poly-, 8-carbonyl (polyketo) acids. Recent versions of this hypothesis propose that the polyketo acid chains can be formed by condensation of one acetyl and several malonyl thiol esters in a manner similar to thecondensation reaction of fatty acid biosynthesis. Properties of three crude syn-thases which support this hypothesis are reviewed: 6-methylsalicylic acid (6-MSA) synthase, alternariol synthase, and orsellinic acid synthase. 6-MSA synthase has been purified about 100-fold and has been shown to be a multi-enzyme complex. Principal problems in studying polyketide synthases include instability of the enzyme preparation and difficulties in reproducibly obtaining cultures with active enzyme. 6-MSA synthase has been stabilized by acetone precipitation, and activity of this enzyme in cultures can be enhancedby low concentrations of cycloheximide.