Specific and nonspecific interactions in ultraweak protein-protein associations revealed by solvent paramagnetic relaxation enhancements.
Specific and nonspecific interactions in ultraweak protein-protein associations revealed by solvent paramagnetic relaxation enhancements.
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DOI：
10.1021/ja503546j
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发表时间：
2014-07-23
影响因子：
15
通讯作者：
Led, Jens J.
中科院分区：
文献类型：
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作者：
Johansson, Helle;Jensen, Malene Ringkjobing;Gesmar, Henrik;Meier, Sebastian;Vinther, Joachim M.;Keeler, Camille;Hodsdon, Michael E.;Led, Jens J.
弱而短暂的蛋白质-蛋白质相互作用是许多生物过程的基础。然而，特定复合物相互作用位点的位置以及瞬时、非特异性蛋白质-蛋白质相互作用的影响通常仍然难以捉摸。我们通过可溶性顺磁弛豫剂钆双酰胺 (Gd(DTPA-BMA)) 诱导的酰胺质子的顺磁弛豫增强 (PRE) 研究了人生长激素 (hGH, KD = 0.90 ± 0.03 mM) 在中性 pH 下的弱自缔合。首先，我们发现，只有考虑到蛋白质溶液中扩散的拥挤效应，PRE 才与通过平移扩散进行弛豫的一般 Hwang-Freed 模型一致 (J. Chem. Phys.1975, 63, 4017–4025)。其次，通过测量在增加的 hGH 浓度和恒定浓度的松弛剂下酰胺质子的 PRE，结果表明，可以区分仅受瞬时、非特异性蛋白质-蛋白质相互作用影响的残基和涉及特定蛋白质-蛋白质关联的残基。因此，前一个残基的 PRE 在整个浓度范围内随 hGH 浓度线性增加，因为瞬时的、非特异性的蛋白质-蛋白质相互作用导致扩散减少，而后一个残基的 PRE 仅在较低的 hGH 浓度下增加，但在较高的浓度下减少，因为特定的蛋白质-蛋白质关联阻碍了钆双酰胺接近相互作用表面的残基。最后，我们发现 hGH 的超弱聚集涉及多个相互作用位点，这些位点位于覆盖大部分蛋白质表面的斑块中。
Weak and transient protein–protein interactions underlie numerous biological processes. However, the location of the interaction sites of the specific complexes and the effect of transient, nonspecific protein–protein interactions often remain elusive. We have investigated the weak self-association of human growth hormone (hGH, KD = 0.90 ± 0.03 mM) at neutral pH by the paramagnetic relaxation enhancement (PRE) of the amide protons induced by the soluble paramagnetic relaxation agent, gadodiamide (Gd(DTPA-BMA)). Primarily, it was found that the PREs are in agreement with the general Hwang-Freed model for relaxation by translational diffusion (J. Chem. Phys.1975, 63, 4017–4025), only if crowding effects on the diffusion in the protein solution are taken into account. Second, by measuring the PREs of the amide protons at increasing hGH concentrations and a constant concentration of the relaxation agent, it is shown that a distinction can be made between residues that are affected only by transient, nonspecific protein–protein interactions and residues that are involved in specific protein–protein associations. Thus, the PREs of the former residues increase linearly with the hGH concentration in the entire concentration range because of a reduction of the diffusion caused by the transient, nonspecific protein–protein interactions, while the PREs of the latter residues increase only at the lower hGH concentrations but decrease at the higher concentrations because of specific protein–protein associations that impede the access of gadodiamide to the residues of the interaction surface. Finally, it is found that the ultraweak aggregation of hGH involves several interaction sites that are located in patches covering a large part of the protein surface.
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Biopython：用于计算分子生物学和生物信息学的免费 Python 工具。
DOI：
10.1093/bioinformatics/btp163
发表时间：
2009-06-01
期刊：
Bioinformatics (Oxford, England)
影响因子：
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作者：
Cock PJ;Antao T;Chang JT;Chapman BA;Cox CJ;Dalke A;Friedberg I;Hamelryck T;Kauff F;Wilczynski B;de Hoon MJ
通讯作者：
de Hoon MJ
影响因子：
2.7
作者：
Dauty, E;Verkman, AS
通讯作者：
Verkman, AS
影响因子：
2.9
作者：
ABILDGAARD, F;JORGENSEN, AMM;DALBOGE, H
通讯作者：
DALBOGE, H
影响因子：
2.4
作者：
Einstein, A
通讯作者：
Einstein, A
影响因子：
--
作者：
LESTER, CC;BRYANT, RG
通讯作者：
BRYANT, RG