Increase in surface hydrophobicity of the cataract-associated P23T mutant of human gammaD-crystallin is responsible for its dramatically lower, retrograde solubility.
Increase in surface hydrophobicity of the cataract-associated P23T mutant of human gammaD-crystallin is responsible for its dramatically lower, retrograde solubility.
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DOI：
10.1021/bi100664s
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发表时间：
2010-07-27
期刊：
影响因子：
2.9
通讯作者：
Pande, Jayanti
中科院分区：
文献类型：
--
作者：
Pande, Ajay;Ghosh, Kalyan S.;Banerjee, Priya R.;Pande, Jayanti
人类 γD-晶状体蛋白 (HGD) 中与白内障相关的 Pro23 到 Thr (P23T) 突变具有多种表型，并且在地理上广泛存在。因此，人们对了解这种突变导致的白内障形成的分子基础非常感兴趣。我们之前展示过 [Pande 等人。 (2005) Biochemistry 44, 2491-2500] 在这种情况下，不透明的可能基础是 P23T 相对于 HGD 的严重受损、逆行溶解度和聚集。即使突变蛋白的结构在体外基本保持不变，溶解度也会发生巨大的变化。我们提出 P23T 的逆行溶解度和聚集是由净疏水性、蛋白质-蛋白质相互作用介导的。基于 P23T 和相关突变体的这些初步发现，以及随后发现它们表现出非典型相行为，我们得出结论，突变蛋白溶液中形成的蛋白簇通过净疏水性、各向异性相互作用保持在一起。在这里，我们使用化学探针表明，这些突变体的表面疏水性与其溶解度成反比。此外，通过直接探测 HGD 和 P23T 的独立 N 端结构域，我们发现 P23T 表面疏水性的增加位于 N 端结构域。模型研究表明，N 端结构域表面存在粘性斑块，可通过疏水性蛋白质-蛋白质相互作用参与形成蛋白质簇。因此，这项工作为净疏水性和各向异性蛋白质-蛋白质相互作用在 P23T 聚集中发挥的主导作用提供了直接证据。
The cataract-associated Pro23 to Thr (P23T) mutation in human γD-crystallin (HGD) has a variety of phenotypes and is geographically widespread. Therefore there is considerable interest in understanding the molecular basis of cataract formation due to this mutation. We showed earlier [Pande, et al. (2005) Biochemistry 44, 2491-2500] that the probable basis of opacity in this case is the severely compromised, retrograde solubility and aggregation of P23T relative to HGD. The dramatic solubility change occurs even as the structure of the mutant protein remains essentially unchanged in vitro. We proposed that the retrograde solubility and aggregation of P23T were mediated by net hydrophobic, protein-protein interactions. Based on these initial findings for P23T and related mutants, and the subsequent finding that they show atypical phase behavior, we concluded that the protein clusters formed in solutions of the mutant proteins were held together by net hydrophobic, anisotropic interactions. Here we show, using chemical probes, that the surface hydrophobicities of these mutants are inversely related to their solubility. Furthermore, by probing the isolated N-terminal domains of HGD and P23T directly, we find that the increase in surface hydrophobicity of P23T is localized in the N-terminal domain. Modeling studies suggest the presence of sticky patches on the surface of the N-terminal domain that could be engaged in forming protein clusters via hydrophobic protein-protein interactions. This work thus provides direct evidence for the dominant role played by net hydrophobic and anisotropic protein-protein interactions in the aggregation of P23T.
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影响因子：
3.7
作者：
Hawe, Andrea;Sutter, Marc;Jiskoot, Wim
通讯作者：
Jiskoot, Wim
影响因子：
--
作者：
Eaton, W A;Hofrichter, J
通讯作者：
Hofrichter, J
DOI：
10.1073/pnas.040554397
发表时间：
2000-02-29
影响因子：
11.1
作者：
Pande, A;Pande, J;Benedek, GB
通讯作者：
Benedek, GB
影响因子：
2.1
作者：
Monera, Oscar D.;Sereda, Terrance J.;Hodges, Robert S.
通讯作者：
Hodges, Robert S.
影响因子：
4
作者：
Santhiya, ST;Manohar, MS;Graw, J
通讯作者：
Graw, J