Comparison of SH3 and SH2 domain dynamics when expressed alone or in an SH(3+2) construct: the role of protein dynamics in functional regulation.
Comparison of SH3 and SH2 domain dynamics when expressed alone or in an SH(3+2) construct: the role of protein dynamics in functional regulation.
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DOI：
10.1006/jmbi.1999.2619
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发表时间：
1999-04
影响因子：
5.6
通讯作者：
John R. Engen;T. Smithgall;William H. Gmeiner;David L. Smith;David L. Smith
中科院分区：
文献类型：
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作者：
John R. Engen;T. Smithgall;William H. Gmeiner;David L. Smith;David L. Smith
蛋白质动力学在蛋白质功能和酶活性调节中起着重要作用。为了确定与周围结构的额外相互作用如何影响局部蛋白质动力学，我们使用氢交换和质谱仪研究了蛋白酪氨酸激酶HCK的SH2和SH3结构域。将分离的HCK SH3和SH2结构域的交换率与相同结构域的交换率进行了比较，这些交换率是较大的SH(3+2)结构的一部分。在关节结构中观察到SH3结构域的氚掺入增加，特别是在SH2界面和连接SH3和SH2的短序列附近，这意味着当SH3是SH(3+2)的一部分时，SH3具有更大的灵活性。SH3结构域在单独的SH3中以与SH(3+2)结构相同的速度缓慢协同展开，这表明这种展开具有功能意义。当SH(3+2)结构的一部分时，SH2结构域的灵活性变化相对较小。这些结果表明，这些结构域相互影响。此外，我们的结果暗示了SH3和SH2结构域的功能调控和结构动力学之间的联系。
Protein dynamics play an important role in protein function and regulation of enzymatic activity. To determine how additional interactions with surrounding structure affects local protein dynamics, we have used hydrogen exchange and mass spectrometry to investigate the SH2 and SH3 domains of the protein tyrosine kinase Hck. Exchange rates of isolated Hck SH3 and SH2 domains were compared with rates for the same domains when part of a larger SH(3+2) construct. Increased deuterium incorporation was observed for the SH3 domain in the joint construct, particularly near the SH2 interface and the short sequence that connects SH3 to SH2, implying greater flexibility of SH3 when it is part of SH(3+2). Slow cooperative unfolding of the SH3 domain occurred at the same rate in isolated SH3 as in the SH(3+2) construct, suggesting a functional significance for this unfolding. The SH2 domain displayed relatively smaller changes in flexibility when part of the SH(3+2) construct. These results suggest that the domains influence each other. Further, our results imply a link between functional regulation and structural dynamics of SH3 and SH2 domains.