Lactate dehydrogenases of Atlantic hagfish: physiological and evolutionary implications of a primitive heart isozyme.
Lactate dehydrogenases of Atlantic hagfish: physiological and evolutionary implications of a primitive heart isozyme.
复制标题
大西洋盲鳗的乳酸脱氢酶：原始心脏同工酶的生理和进化意义。
DOI：
10.1126/science.7352286
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发表时间：
1980
期刊：
影响因子：
56.9
通讯作者：
K. Beland
中科院分区：
文献类型：
--
作者：
B. Sidell;K. Beland
大西洋盲鳗心脏和肌肉乳酸脱氢酶同工酶的功能分化程度低于其它鱼类和高等脊椎动物。与其他物种的心脏同工酶相比，来自盲鳗心脏的酶（B4）显示出较高的丙酮酸米氏常数和在中等丙酮酸浓度下较低的底物抑制。这些特性支持了这一假设，即祖先脊椎动物乳酸脱氢酶是一种肌肉（A4）型酶，也表明B4酶的作用，在不寻常的生理功能，在持续缺氧条件下的盲鳗心脏组织。
Isozymes of lactate dehydrogenase from heart and muscle of Atlantic hagfish show less functional divergence than those from other fishes and higher vertebrates. The enzyme from hagfish heart (B4) displays a higher Michaelis constant for pyruvate and lower substrate inhibition at moderate pyruvate concentrations than heart isozymes from other species. These properties support the hypothesis that the ancestral vertebrate lactate dehydrogenase was a muscle (A4)-type enzyme and also suggest a role for the B4 enzyme in the unusual physiology of hagfish cardiac tissue which functions under sustained hypoxic conditions.