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Abstract

Grant Number:	2R44GM064841-02
PI Name:	NOVICK, SCOTT J.
PI Email:	sjnovick@biocatalytics.com
PI Title:
Project Title:	Deracemization of Amino Acids

Abstract: DESCRIPTION (provided by applicant): Unnatural amino acids (UAAs) are increasingly becoming important pharmaceutical intermediates, with applications in a number of current and future drugs. Since UAAs are almost always required as pure stereoisomers, a chiral synthesis is preferred over the resolution methods that are most commonly employed. In Phase I the single-pot deracemization process to make the L-enantiomer was demonstrated. In this method the D-enantiomer of a D,L-amino acid mixture is selectively oxidized to the corresponding 2- ketoacid using a D-amino acid oxidase. The 2-ketoacid is then stereoselectively aminated to the L-amino acid by an L-amino acid transaminase or an L-amino acid dehydrogenase. This is accomplished in a reaction single step, intermediates need not be isolated nor is it necessary for protecting groups or derivatization. Yields and enantiomeric excess values approach 100 percent. This method has a broad scope and will be applicable to a wide range of UAA products. Directed evolution was used on a number of the enzymes investigated to create more active enzyme mutants. In Phase II the deracemization process will be further characterized and optimized. Directed evolution will be performed on a number of the enzymes to create mutants with enhanced activity and broader substrate specificity. In addition, the deracemization of amino acids to make the pure D-enantiomer will be investigated. Both methods, for making the pure L- or D-enantiomer will be demonstrated on the 100 gram scale for important commercial targets.

Thesaurus Terms:
aminoacid, aminoacid oxidase, chemical synthesis, method development, racemization, stereoisomer
enzyme activity, enzyme substrate, immobilized enzyme, ketoacid, transaminase
directed evolution

Institution:	BIOCATALYTICS, INC.
	129 N HILL AVE, STE 103
	PASADENA, CA 911051955
Fiscal Year:	2003
Department:
Project Start:	01-FEB-2002
Project End:	28-FEB-2005
ICD:	NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES
IRG:	ZRG1

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