Structural and thermodynamic basis of (+)-α-pinene binding to human cytochrome P450 2B6.
Structural and thermodynamic basis of (+)-α-pinene binding to human cytochrome P450 2B6.
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DOI：
10.1021/ja403042k
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发表时间：
2013-07-17
影响因子：
15
通讯作者：
Halpert, James R.
中科院分区：
文献类型：
--
作者：
Wilderman, P. Ross;Shah, Manish B.;Jang, Hyun-Hee;Stout, C. David;Halpert, James R.
尽管最近在原子水平上了解药物和抑制剂与人类细胞色素P450的相互作用方面取得了进展，但数十年来碳氢化合物结合的化学和结构决定因素的问题仍然没有答案。（+）-α-蒎烯是一种广泛分布于环境中的单萜烃类化合物，是一种有效的P450 2B抑制剂。因此，对人P450 2B 6与（+）-α-蒎烯的相互作用进行了生物物理和结构分析，以阐明极高亲和力结合的基础。（+）-α-蒎烯与P450活性位点的结合由I型光谱位移证明。使用等温滴定量热法探索配体结合的热力学，并与P450 2A 6的热力学进行比较，基于多种X射线晶体结构的比较，P450 2A 6的灵活性比2B 6低得多。与预期一致，熵是碳氢化合物与P450 2A 6结合的主要驱动力，如量热结果所证明的。然而，2B 6-（+）-α-蒎烯复合物的形成具有显著的非质子组分。该酶配体复合物的2.0 μ m分辨率晶体结构显示，高度可塑的2B 6利用了以前未识别的蛋白质基序重排。结果表明，特定的组分对配体结合的贡献与酶的柔性程度密切相关。
Despite recent advances in atomic level understanding of drug and inhibitor interactions with human cytochromes P450, the decades-old questions of chemical and structural determinants of hydrocarbon binding are still unanswered. (+)-α-Pinene is a monoterpene hydrocarbon that is widely distributed in the environment and a potent P450 2B inhibitor. Therefore, a combined biophysical and structural analysis of human P450 2B6 interactions with (+)-α-pinene was undertaken to elucidate the basis of the very high affinity binding. Binding of (+)-α-pinene to the P450 active site was demonstrated by a Type I spectral shift. Thermodynamics of ligand binding were explored using isothermal titration calorimetry and compared to those of P450 2A6, which is much less flexible than 2B6 based on comparison of multiple X-ray crystal structures. Consistent with expectation, entropy is the major driving force for hydrocarbon binding to P450 2A6, as evidenced by the calorimetric results. However, formation of the 2B6-(+)-α-pinene complex has a significant enthalpic component. A 2.0 Å resolution crystal structure of this enzyme ligand complex reveals that the highly plastic 2B6 utilizes previously unrecognized rearrangements of protein motifs. The results indicate that the specific components of enthalpic contribution to ligand binding are closely tied to the degree of enzyme flexibility.
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影响因子：
2.9
作者：
Gay SC;Zhang H;Wilderman PR;Roberts AG;Liu T;Li S;Lin HL;Zhang Q;Woods VL Jr;Stout CD;Hollenberg PF;Halpert JR
通讯作者：
Halpert JR
DOI：
10.1073/pnas.1221442110
发表时间：
2013-03-26
影响因子：
11.1
作者：
Lee, Sung Chang;Bennett, Brad C.;Zhang, Qinghai
通讯作者：
Zhang, Qinghai
DOI：
10.1107/s090744499900846x
发表时间：
1999-10-01
期刊：
ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY
影响因子：
--
作者：
Leslie, AGW
通讯作者：
Leslie, AGW
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
1.6
作者：
Miyazawa, M;Sugie, A;Shindo, M
通讯作者：
Shindo, M