Allen M D, Perham R N
Cambridge Centre for Molecular Recognition, Department of Biochemistry, University of Cambridge, UK.
FEBS Lett. 1997 Aug 18;413(2):339-43. doi: 10.1016/s0014-5793(97)00932-0.
A sub-gene encoding the catalytic (acetyltransferase) domain (E2pCD) comprising residues 173-427 of the dihydrolipoyl acetyltransferase (E2p) chain of the pyruvate dehydrogenase multienzyme complex of Bacillus stearothermophilus was expressed in Escherichia coli. The product assembled to form the characteristic icosahedral (60-mer) core structure with full catalytic activity. The Km values for dihydrolipoamide and acetyl-CoA were 1.2 mM and 13 microM, respectively. Dissociation of the icosahedral E2pCD into monomers by exposure to guanidine hydrochloride and the subsequent reassociation by gradual removal of the denaturing agent demonstrated the ability of the polypeptide chain to fold and reassemble in the absence of chaperonins.
编码嗜热脂肪芽孢杆菌丙酮酸脱氢酶多酶复合体二氢硫辛酰胺乙酰转移酶（E2p）链173 - 427位残基的催化（乙酰转移酶）结构域（E2pCD）的亚基因在大肠杆菌中表达。产物组装形成具有完整催化活性的特征性二十面体（60聚体）核心结构。二氢硫辛酰胺和乙酰辅酶A的米氏常数分别为1.2 mM和13 μM。通过暴露于盐酸胍使二十面体E2pCD解离成单体，随后通过逐渐去除变性剂使其重新缔合，这证明了多肽链在没有伴侣蛋白的情况下折叠和重新组装的能力。
