König G, Razzoli L, Astancolle S, Cennamo C
Ital J Biochem. 1977 Nov-Dec;26(6):473-86.
The molecular weight of NAD-specific isocitrate dehydrogenase, purified from baker's yeast, has been studied by molecular sieve chromatography. By elution of the enzyme from columns of Sepharose 6B with 0.05 M phosphate buffer, pH 7.6, a mol. wt of 151,000 was measured. Higher values of the mol. wt were measured in presence of the following ligands (mol. wt in parentheses): the substrate, isocitrate (224,000); the activators, citrate (203,000) and AMP (275,000); the inhibitor, NaCl (360,000). A mol. wt of 337,000 was measured when AMP, which antagonizes the inhibition by chloride, was present together with NaCl. The results indicate the absence of a correlation between the aggregation form of the enzyme in presence of the ligands and the effects of these ligands on the enzyme activity.
通过分子筛色谱法研究了从面包酵母中纯化得到的NAD特异性异柠檬酸脱氢酶的分子量。用pH 7.6的0.05 M磷酸盐缓冲液从琼脂糖6B柱上洗脱该酶，测得分子量为151,000。在存在以下配体的情况下测得的分子量较高（括号内为分子量）：底物异柠檬酸（224,000）；激活剂柠檬酸（203,000）和AMP（275,000）；抑制剂NaCl（360,000）。当与氯化物拮抗抑制作用的AMP与NaCl同时存在时，测得分子量为337,000。结果表明，在配体存在下酶的聚集形式与这些配体对酶活性的影响之间不存在相关性。
