Snapshots of the Catalytic Cycle of the Industrial Enzyme α-Amino-ε-Caprolactam Racemase (ACLR) Observed Using X-ray Crystallography

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• 作者：Amina Frese ; Peter W. Sutton ; Johan P. TurkenburgGideon Grogan
• 刊名：ACS Catalysis
• 出版年：2017
• 出版时间：February 3, 2017
• 年：2017
• 卷：7
• 期：2
• 页码：1045-1048
• 全文大小：299K
• ISSN：2155-5435

文摘

α-Amino-ε-caprolactam racemase (ACLR) is a PLP-dependent enzyme exploited in industry for the racemization of amino acid amides in dynamic kinetic resolutions that produce homochiral amino acids. We report high-resolution structures of wild-type and variant ACLRs from Rhizobium freirei, generated using the chiral substrate ACL and representative of covalent intermediates in the catalytic cycle. These complexes substantiate suggestions of a two-base mechanism, in which the PLP-binding K267 and D210 serve as proton donors in the racemization, and they constitute a robust basis on which to engineer ACLRs for improved activity as industrial biocatalysts.