Acyl-CoA Synthetase in Maturing Safflower Seeds
Acyl-CoA Synthetase in Maturing Safflower Seeds
复制标题
成熟红花种子中的酰基辅酶A合成酶
DOI：
10.1093/oxfordjournals.pcp.a078455
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发表时间：
1993
影响因子：
4.9
通讯作者：
Kunisuke Tanaka
中科院分区：
文献类型：
--
作者：
K. Ichihara;M. Nakagawa;Kunisuke Tanaka
红花成熟种子中的酰基辅酶A合成酶是膜结合的，最高比活性与微粒体有关。活性完全依赖于脂肪酸、CoA、ATP和Mg ~（2+）的浓度。油酸、CoA和ATP的表观Km值分别为4.2 μM、24 μM和250 μM。反应的最适pH为7.5。Triacsin C是动物和细菌酰基辅酶A合成酶的有效抑制剂，对红花酶无效。该酶优先利用C16和C18长链脂肪酸，而中链和超长链脂肪酸是不良底物。天然脂肪酸的特异性顺序为亚油酸酯>油酸酯=棕榈酸酯>硬脂酸酯。虽然每个种子的活性在种子成熟过程中变化，但足以说明体内三酰甘油合成的速率。
Acyl-CoA synthetase in maturing seeds of safflower (Carthamus tinctorius) was membranebound, and the highest specific activity was associated with microsomes. Activity absolutely depended on the concentrations of fatty acid, CoA, ATP and Mg2+. The apparentKmvalues were 4.2 μM for oleate, 24 μM for CoA, and 250 μM for ATP. The optimum pH of the reaction was 7.5. Triacsin C, a potent inhibitor of the animal and bacterial acyl-CoA synthetase, was ineffective for the safflower enzyme. The enzyme utilized C16and C18long-chain fatty acids preferentially, while medium-chain and very-long-chain fatty acids were poor substrates. The order of specificity for native fatty acids was linoleate > oleate=palmitate > stearate. Although activity per seed varied during seed maturation, it was enough to account for the rate of triacylglycerol synthesis in vivo.