Structural Insights into the Hydrolysis and Polymorphism of Methotrexate Polyglutamate by Zebrafish 纬-Glutamyl Hydrolase

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• 作者：Phimonphan Chuankhayan ; Tseng-Ting Kao ; Chien-Chih Lin ; Hong-Hsiang Guan ; Atsushi Nakagawa ; Tzu-Fun Fu ; Chun-Jung Chen
• 刊名：Journal of Medicinal Chemistry
• 出版年：2013
• 出版时间：October 10, 2013
• 年：2013
• 卷：56
• 期：19
• 页码：7625-7635
• 全文大小：532K
• 年卷期：v.56,no.19(October 10, 2013)
• ISSN：1520-4804

文摘

纬-Glutamyl hydrolases (纬GH) catalyze the hydrolysis of 纬-linked glutamate residues from the polyglutamyl of folates and antifolates, such as methotrexate (MTX), a widely used anticancer drug. We describe the first crystal structures of the endopeptidase-type 纬GH (z纬GH) from zebrafish and the mutant complexes with MTX(Glu)₅ and hydrolyzed MTX(Glu)₁, revealing the complete set of key residues involved in hydrolysis as well as the substrate-binding subsites (鈭? to +2). The side chain of Phe20 and the 6-methylpterin ring of MTX(Glu)₅ invoke 蟺鈥撓€ interactions to promote distinct concerted conformational alterations involving 90掳 rotations in the complexes with the z纬GH-C108A and z纬GH-H218N mutant proteins. The structural geometries of the MTX(Glu)₅ and hydrolyzed MTX(Glu)₁ in the mutant complexes differ significantly from those of the previously known MTX(Glu)₁, providing polymorphic information. Together with the structural comparison and the activity analysis, these results shed light on the catalytic mechanism and substrate recognition of z纬GH and other 纬-glutamyl hydrolases.