Hiromasa Y, Aso Y, Yamashita S, Aikawa Y, Ishiguro M
Laboratory of Protein Chemistry and Engineering, Graduate School of Genetic Resources Technology, Kyushu University, Fukuoka, Japan.
Biosci Biotechnol Biochem. 1997 Jul;61(7):1126-32. doi: 10.1271/bbb.61.1126.
Thermally induced changes in pyruvate dehydrogenase complex (PDC) from B. stearothermophilus were examined mainly at temperatures from 60 degrees to 70 degrees C. Accompanied by inactivation of pyruvate decarboxylase, light scattering decreased, and ANS fluorescence increased. These changes including the inactivation were approximately first-order reactions, and the values of rate constants were greatly dependent on temperature. Chromatographic studies showed that any polypeptides were in associated forms and that final products were aggregates (> 230S) and an assembly (48S) smaller than PDC. The aggregates and assembly were rich in decarboxylase and lipoate acetyltransferase, respectively. It was suggested that, during the thermal denaturation, a decarboxylase was dissociated from PDC and immediately involved in aggregates.
主要在60℃至70℃的温度范围内研究了嗜热脂肪芽孢杆菌丙酮酸脱氢酶复合体（PDC）的热诱导变化。伴随着丙酮酸脱羧酶的失活，光散射降低，而ANS荧光增加。包括失活在内的这些变化近似为一级反应，速率常数的值强烈依赖于温度。色谱研究表明，所有多肽均以缔合形式存在，最终产物是聚集体（>230S）和比PDC小的装配体（48S）。聚集体和装配体分别富含脱羧酶和硫辛酸乙酰转移酶。有人提出，在热变性过程中，一种脱羧酶从PDC上解离下来并立即参与聚集体的形成。
