共 26 条
φ value analysis of heterogeneity in pathways of allosteric transitions:: Evidence for parallel pathways of ATP-induced conformational changes in a GroEL ring
被引:19
作者:
Horovitz, A
[1
]
Amir, A
[1
]
Danziger, O
[1
]
Kafri, G
[1
]
机构:
[1] Weizmann Inst Sci, Dept Biol Struct, IL-76100 Rehovot, Israel
来源:
关键词:
nested allostery;
cooperativity;
chaperonins;
D O I:
10.1073/pnas.222303299
中图分类号:
O [数理科学和化学];
P [天文学、地球科学];
Q [生物科学];
N [自然科学总论];
学科分类号:
07 ;
0710 ;
09 ;
摘要:
What are the mechanisms of ligand-induced allosteric transitions in proteins? A powerful method to characterize pathways and transition states of reactions is phi value analysis. A phi value is the ratio between the changes on a perturbation (e.g., mutation) in the activation and equilibrium free energies of a reaction. Here, phi value analysis is used to characterize the ATP-induced allosteric transitions of GroEL by using changes in ATP concentration as perturbations. GroEL consists of two stacked back-to-back heptameric rings that bind ATP with positive cooperativity within rings and negative cooperativity between rings. Evidence is presented for the existence of parallel pathways for the allosteric transition of each ring. In both allosteric transitions, there is an abrupt ATP-dependent switch from a pathway with ATP-binding sites in the transition state that are very similar to those of the initial T state (phi = 0) to a pathway with a phi value of approximate to0.3. The phi value procedure outlined here should be useful in mapping the energy landscape of allosteric transitions of other proteins.
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页码:14095 / 14097
页数:3
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