Malate transport in Schizosaccharomyces pombe
Malate transport in Schizosaccharomyces pombe
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粟酒裂殖酵母中的苹果酸转运
DOI：
10.1128/jb.168.3.1439-1443.1986
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发表时间：
1986
影响因子：
3.2
通讯作者：
R. Subden
中科院分区：
文献类型：
--
作者：
C. Osothsilp;R. Subden
研究了粟酒裂殖酵母野生型菌株和不能利用苹果酸的突变菌株中苹果酸的转运。两组这样的突变体，苹果酸酶缺陷型和苹果酸转运缺陷型突变体，通过14 C标记的L-苹果酸转运测定和淀粉凝胶电泳，然后对苹果酸酶（苹果酸脱氢酶[草酰乙酸脱羧] [NAD+]; 1.1.1.38）和苹果酸脱氢酶（1.1.1.37）进行活性染色来区分。苹果酸在S.粟酒裂殖酵母是组成型的，并且被氧化磷酸化和质子梯度制剂的抑制剂强烈抑制。运输是苹果酸浓度的饱和函数。由父母运输的表观Km和Vmax值分别为3.7 mM和40 nmol/min/mg蛋白质，而苹果酸酶缺陷突变体分别为5.7 mM和33 nmol/min/mg蛋白质。苹果酸的运输是pH和温度依赖性的。运输的特异性进行了研究与各种基板，包括单和二羧酸，和一个共同的运输系统的二羧酸的可能性进行了讨论。
The transport of malate was studied in a Schizosaccharomyces pombe wild-type strain and in mutant strains unable to utilize malic acid. Two groups of such mutants, i.e., malic enzyme-deficient and malate transport-defective mutants, were differentiated by a 14C-labeled L-malate transport assay and by starch gel electrophoresis followed by activity staining for malic enzyme (malate dehydrogenase [oxaloacetate decarboxylating] [NAD+]; 1.1.1.38) and malate dehydrogenase (1.1.1.37). Transport of malate in S. pombe was constitutive and strongly inhibited by inhibitors of oxidative phosphorylation and of the formulation of proton gradients. Transport was a saturable function of the malate concentration. The apparent Km and Vmax values for transport by the parent were 3.7 mM and 40 nmol/min per mg of protein, respectively, while those of the malic enzyme-deficient mutant were 5.7 mM and 33 nmol/min per mg of protein, respectively. Malate transport was pH and temperature dependent. The specificity of transport was studied with various substrates, including mono- and dicarboxylic acids, and the possibility of a common transport system for dicarboxylic acids is discussed.