印度棘蜥睾丸中乳酸脱氢酶的同工酶形式。

The isoenzyme forms of lactate dehydrogenase from the testes of Uromastix hardwickii.

作者信息

Javed M H, Qureshi M A, Waqar M A

机构信息

Department of Biochemistry, Aga Khan University Medical College, Karachi, Pakistan.

出版信息

Biochem Mol Biol Int. 1994 Nov;34(5):963-70.

PMID:7703913

Abstract

Lactate dehydrogenase was purified from testes of Uromastix hardwickii. The enzyme did not bind to DEAE-Sepharose at pH 7.2. A gel electrophoretic study of the crude enzyme showed the presence of three isoenzymes. The pH optima for pyruvate reduction and lactate oxidation were 7.0 and 9.5, respectively. The purified enzyme showed a single band after SDS-PAGE corresponding to a molecular weight of 34 KDa. The Km values for pyruvate, NADH, lactate and NAD+ were 0.019, 0.045, 9.0 and 0.011 mM, respectively. Pre-heating of the enzyme showed that it was stable up to 70 degrees C.

摘要

从硬尾沙蜥的睾丸中纯化出乳酸脱氢酶。该酶在pH 7.2时不与DEAE-琼脂糖结合。对粗酶进行的凝胶电泳研究显示存在三种同工酶。丙酮酸还原和乳酸氧化的最适pH分别为7.0和9.5。纯化后的酶在SDS-PAGE后呈现单一条带，对应分子量为34 kDa。丙酮酸、NADH、乳酸和NAD⁺的Km值分别为0.019、0.045、9.0和0.011 mM。酶的预热表明其在高达70摄氏度时稳定。