Jayalakshmi V, Krishna N Rama
Department of Biochemistry and Molecular Genetics and the NMR Core Facility, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama 35294-2041, USA.
J Am Chem Soc. 2005 Oct 12;127(40):14080-4. doi: 10.1021/ja054192f.
Dihydrofolate reductase (DHFR) is a pharmacologically important intracellular target enzyme for folate antagonists, including the antibacterial agent trimethoprim (TMP). The structures of DHFR from various sources with and without the bound ligands have been determined by X-ray crystallography and solution NMR spectroscopy. However, there is no crystal or solution NMR structure for the bovine DHFR/TMP complex. Here we report the solution structure of TMP within the binding pocket of bovine DHFR using a novel method developed in our laboratory, viz., STD-NMR intensity-restrained CORCEMA-ST optimization (SICO) utilizing experimental STD data on this complex, and demonstrate that its solution structure is essentially identical to the one in the crystal structure of the homologous chicken liver DHFR/TMP complex. The excellent agreement we obtain between the experimental and predicted STDs also serves as a validation of the CORCEMA-ST methodology.
二氢叶酸还原酶（DHFR）是一种在药理学上具有重要意义的细胞内靶酶，可作用于包括抗菌剂甲氧苄啶（TMP）在内的叶酸拮抗剂。通过X射线晶体学和溶液核磁共振光谱法已经确定了来自各种来源的、结合或未结合配体的DHFR结构。然而，尚无牛DHFR/TMP复合物的晶体或溶液核磁共振结构。在此，我们使用我们实验室开发的一种新方法，即利用该复合物的实验性饱和转移差（STD）数据进行的STD-核磁共振强度约束的CORCEMA-ST优化（SICO），报道了TMP在牛DHFR结合口袋内的溶液结构，并证明其溶液结构与同源鸡肝DHFR/TMP复合物晶体结构中的结构基本相同。我们在实验性和预测性STD之间获得的出色一致性也验证了CORCEMA-ST方法。
