Molecular characterization of the group II chaperonin from the hyperthermophilic archaeum Pyrococcus horikoshii OT3
Molecular characterization of the group II chaperonin from the hyperthermophilic archaeum Pyrococcus horikoshii OT3
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DOI：
10.1007/s00792-004-0427-y
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发表时间：
2005-04-01
期刊：
影响因子：
2.9
通讯作者：
Yohda, M
中科院分区：
文献类型：
--
作者：
Okochi, M;Matsuzaki, H;Yohda, M
研究了来自超嗜热古菌 Pyrococcus horikoshii OT3 (PhCPN) 的 II 类伴侣蛋白及其与同源前折叠蛋白的功能配合。 PhCPN 以双环结构的同源寡聚物形式存在，可保护猪心脏的柠檬酸合酶在 45 摄氏度下不发生热聚集，并且对嗜热细菌（嗜热栖热菌 HB8）的异丙基苹果酸脱氢酶（IPMDH）在 90 摄氏度下也有同样的作用。PhCPN 还增强了在低 pH 条件下解折叠的绿色荧光蛋白（GFP）的重折叠。 ATP依赖方式。出乎意料的是，没有观察到 PhCPN 和火球菌预折叠蛋白 (PhPFD) 在 GFP 重折叠中的功能合作。相反，在用盐酸胍解折叠的 IPMDH 重折叠中观察到 PhCPN 和 PhPFD 之间的合作。虽然单独使用 PhCPN 不能有效地促进 IPMDH 的重折叠，但 PhCPN 与 PhPFD 的配合可提高重折叠效率。
The group II chaperonin from the hyperthermophilic archaeum Pyrococcus horikoshii OT3 (PhCPN) and its functional cooperation with the cognate prefoldin were investigated. PhCPN existed as a homo-oligomer in a double-ring structure, which protected the citrate synthase of a porcine heart from thermal aggregation at 45 degrees C, and did the same on the isopropylmalate dehydrogenase (IPMDH) of a thermophilic bacterium, Thermus thermophilus HB8, at 90 degrees C. PhCPN also enhanced the refolding of green fluorescent protein (GFP), which had been unfolded by low pH, in an ATP-dependent manner. Unexpectedly, functional cooperation between PhCPN and Pyrococcus prefoldin (PhPFD) in the refolding of GFP was not observed. Instead, cooperation between PhCPN and PhPFD was observed in the refolding of IPMDH unfolded with guanidine hydrochloride. Although PhCPN alone was not effective in the refolding of IPMDH, the refolding efficiency was enhanced by the cooperation of PhCPN with PhPFD.