Assisted folding of D-glyceraldehyde-3-phosphate dehydrogenase by trigger factor
Assisted folding of D-glyceraldehyde-3-phosphate dehydrogenase by trigger factor
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DOI：
10.1110/ps.9.6.1254
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发表时间：
2000-06-01
期刊：
影响因子：
8
通讯作者：
Fischer, G
中科院分区：
文献类型：
--
作者：
Huang, GC;Li, ZY;Fischer, G
大肠杆菌触发因子是一种肽基-脯氨酰顺反异构酶，可以很好地催化脯氨酸限制的蛋白质折叠。这里。研究了触发因子存在下 D-甘油醛-3-磷酸脱氢酶 (GAPDH) 的重折叠。长期或短期变性后，触发因子显着增加了 GAPDH 的活性恢复，并且阻止了可检测到的 GAPDH 中间体的聚集。在沐浴情况下，GAPDH 重折叠的时间进程因触发因素而减慢。当触发因子与GAPDH的摩尔比高于5时，由于较大的因子与GAPDH中间体之间的紧密结合，GAPDH的再激活产率表现出缓慢的下降趋势。通过添加还原的αLA作为竞争剂、通过进一步稀释重折叠混合物或通过破坏复合物中的疏水相互作用，可以部分地从触发因子中拯救这种无活性的结合GAPDH。提出了触发因子辅助 GAPDH 重折叠的模型。我们还认为nt GAPDH的辅助重折叠主要是由于触发因子的伴侣功能。
The Escherichia coli trigger factor is a peptidyl-prolyl cis-trans isomerase that catalyzes proline-limited protein folding extremely well. Here. refolding of D-glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in the presence of trigger factor was investigated. The regain of activity of GAPDH was markedly increased by trigger factor after either long-or short-term denaturation, and detectable aggregation of GAPDH intermediates was prevented. In bath cases, time courses of refolding of GAPDH were decelerated by trigger factor. The reactivation yield of GAPDH showed a slow down-turn when molar ratios of trigger factor to GAPDH were above 5, due to tight binding between bigger factor and GAPDH intermediates. Such inactive bound GAPDH could be partially rescued from trigger factor by addition of reduced alpha LA as competitor, by further diluting the refolding mixture, or by disrupting hydrophobic interactions in the complexes. A model for trigger factor assisted refolding of GAPDH is proposed. We also suggest that assisted refolding nt GAPDH is due mainly to the chaperone function of trigger factor.