Designing protein dimerizers: The importance of ligand conformational equilibria
Designing protein dimerizers: The importance of ligand conformational equilibria
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DOI：
10.1021/ja026264y
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发表时间：
2003-02-12
影响因子：
15
通讯作者：
Wagner, CR
中科院分区：
文献类型：
--
作者：
Carlson, JCT;Kanter, A;Wagner, CR
为了阐明配体构象在诱导蛋白质二聚中的作用，我们合成了一种灵活的甲氨蝶呤(MTX)二聚体，证明了其选择性二聚化大肠杆菌二氢叶酸还原酶(DHFR)的能力，并评价了调节其诱导二聚化能力的因素。尽管存在已知的势垒，但双MTX在水溶液中仍具有良好的构象稳定性(-3.8kcal/mol大于或等于DeltaG(乘积)大于或等于-4.9kcal/mol)，对二聚反应的热力学起主导作用。为了使DHFR二聚化，bis-MTX必须从折叠构象转变为延伸构象。根据这一结论，可以确定Bis-MTX-E.ColiDHFR二聚体(大于或等于DeltaG(C)大于或等于-4.2kcal/mol)中有利的蛋白质-蛋白质相互作用的强度，以及大肠杆菌DHFR相对于小鼠DHFR的二聚选择性(>；10(7))。双-甲氨蝶呤与大肠杆菌DHFR络合物的晶体结构证实了紧密堆积二聚界面的可行性，并为诱导蛋白晚餐提供了可能的溶液构象。因此，这种最小的Folamer的二级结构调节其在溶液中二聚二氢叶酸还原酶的能力，从而提供了对诱导二聚的复杂能量格局的洞察。
In an effort to elucidate the role of ligand conformation in induced protein dimerization, we synthesized a flexible methotrexate (MTX) dimer, demonstrated its ability to selectively dimerize Escherichia coli dihydrofolate reductase (DHFR), and evaluated the factors regulating its ability to induce cooperative dimerization. Despite known entropic barriers, bis-MTX proved to possess substantial conformational stability in aqueous solution (-3.8 kcal/mol greater than or equal to DeltaG(fold) greater than or equal to -4.9 kcal/mol), exerting a dominant influence on the thermodynamics of dimerization. To dimerize DHFR, bis-MTX must shift from a folded to an extended conformation. From this conclusion, the strength of favorable protein-protein interactions in bis-MTX-E coli DHFR dimers (-3.1 kcal/mol greater than or equal to DeltaG(c) greater than or equal to -4.2 kcal/mol), and the selectivity of dimerization for E coli DHFR relative to mouse DHFR (>10(7)) could be determined. The crystal structure of bis-MTX in complex with E coli DHFR confirms the feasibility of a close-packed dimerization interface and suggests a possible solution conformation for the induced protein dinners. Consequently, the secondary structure of this minimal foldamer regulates its ability to dimerize dihydrofolate reductase in solution, providing insight into the complex energy landscape of induced dimerization.