RELATIONSHIP OF PRIMER SPECIFICITY OF FATTY-ACID DENOVO SYNTHETASE TO FATTY-ACID COMPOSITION IN 10 SPECIES OF BACTERIA AND YEASTS
RELATIONSHIP OF PRIMER SPECIFICITY OF FATTY-ACID DENOVO SYNTHETASE TO FATTY-ACID COMPOSITION IN 10 SPECIES OF BACTERIA AND YEASTS
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DOI：
10.1139/m80-155
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发表时间：
1980-01-01
影响因子：
2.8
通讯作者：
SMITH, EJ
中科院分区：
文献类型：
--
作者：
KANEDA, T;SMITH, EJ
测定了6种细菌和4种酵母菌油脂的脂肪酸组成。研究了脂肪酸从头合成酶对各种链长的酰基-CoA引物的链长特异性。四种细菌（枯草芽孢杆菌、环己棒状杆菌、藤黄微球菌和嗜麦芽假单胞菌）具有iso和anteiso系列的支链脂肪酸作为主要酸。来自这些生物体的从头合成酶对引物的链长表现出特异性，顺序为丁酰-CoA>丙酰-CoA. mchgt。乙酰辅酶A其余的2种细菌和所有4种酵母仅具有直链型脂肪酸，并分为2组：大肠杆菌B、荧光假单胞菌和酿酒酵母，它们以乙酰-CoA>丙酰-CoA. mchgt的顺序利用引物。丁酰辅酶A;和清酒假丝酵母（Candida sake），C.热带红酵母和红酵母，其显示丙酰-CoA>乙酰-CoA. mchgt的顺序。丁酰辅酶A L-α-酮-β-戊酸甲酯是支链型引物的前体，可作为支链型微生物合成脂肪酸的引物来源，而直链型微生物则不能。结果表明，具有直链脂肪酸的生物体缺乏支链等价物，原因有二：首先，它们的酶对具有多于3个C的引物没有活性，其次，它们缺乏提供合适的支链引物的系统。看来，来自具有直链脂肪酸的生物体的从头合成酶的活性通常比来自具有支链脂肪酸的生物体的从头合成酶的活性高得多。
Fatty acid compositions of lipids from 6 bacteria and 4 yeasts were determined. Fatty acid de novo synthetases were investigated with respect to chain length specificity towards acyl-CoA primers of various chain lengths. Four species of bacteria (Bacillus subtilis, Corynebacterium cyclohexanicum, Micrococcus luteus and Pseudomonas maltophilia) possess branched-chain fatty acids of the iso and anteiso series as the major acids. De novo synthetases from these organisms exhibited specificity towards the chain length of the primer in the order butyrl-CoA > propionyl-CoA .mchgt. acetyl-CoA. The remainder, 2 bacteria and all 4 yeasts, have the straight-chain type of fatty acids only and fall into 2 groups: Escherichia coli B, P. fluorescens and Saccharomyces cerevisiae, which utilize the primers in the order acetyl-CoA > propionyl-CoA .mchgt. butyryl-CoA; and Candida sake, C. tropicalis and Rhodotorula glutinis, which show the order propionyl-CoA > acetyl-CoA .mchgt. butyryl-CoA. L-.alpha.-keto-.beta.-Methylvalerate, a precursor of the branched-chain primers, can be used as a source of primer for fatty acid synthesis by the organisms with branched-chain acids but not by those with the straight-chain type. The results indicate that organisms having straight-chain fatty acids lack the branched-chain equivalents for 2 reasons: firstly, their enzymes are not active toward primers with more than 3 C, and secondly, they lack a system of supplying suitable branched-chain primers. It appears that activities of de novo synthetases from the organisms having straight-chain fatty acids generally have much higher activities than those from the organisms possessing branched-chain fatty acids.