Benzaldehyde lyase from pseudomonas fluorescens biovar i mediated biotransformation for the synthesis of chiral alpha hydroxy ketones

Hoşrik, Birsu Semra
Optically active α-hydroxy ketones are important subunits of many biologically active compounds and indispensable synthons for asymmetric synthesis. Benzaldehyde Lyase from Pseudomonas fluorescens Biovar I is a novel ThDP-dependent enzyme that catalyzes the synthesis of benzoin type chiral α-hydroxy ketones starting from both benzaldehyde and racemic benzoin derivatives. Benzaldehyde Lyase is the first example of enzymes in the literature which leads to a chemical resolution of enantiomers of benzoin derivatives through a C-C bond cleavage reaction. Chiral 2-hydroxypropiophenone derivatives are formed by benzaldehyde lyase (BAL), catalyzing C-C bond formation after a selective C-C bond cleavage of a benzoin derivative accepted as a substrate. The enzyme uses only the (R)-benzoin derivatives as substrate for the formation of (R)-HPP derivatives and it is highly stereoselective. Thus, in the presence of the acetaldehyde as the acceptor aldehyde, the C-C bond cleavage of the benzoin molecule followed by the carboligation of the acetaldehyde to yield chiral 2-hydroxy propiophenone derivatives. Given the racemic benzoin to the enzyme as the substrate in the presence of acetaldehyde, both the racemic resolution of the substrate, revealing the unreacted (S)-Benzoin and the formation of the corresponding R-HPP occur.


KOCABIVIK, S; PERLIN, MH (Elsevier BV, 1994-01-01)
1. Oligonucleotide-directed mutagenesis of APH(3')-II was used to investigate the functions of key amino acids in the P-loop analogous motif of the enzyme. 2. The mutations of Gly205 --> GIu, Gly210 --> Ala and Arg211 --> Pro considerably reduced the resistance of the resulting strains to KM and to related drugs, e.g. G418. 3. Similarly, enzyme activity in the crude extracts of these mutants was substantially reduced as well as the enzyme's affinity for Mg2+ ATP. 4. Alternatively substitutions at a highly c...
Unnatural amino acid replacement in a yeast G protein-coupled receptor in its native environment.
Huang, LY; Umanah, G; Hauser, M; Son, Çağdaş Devrim; Arshava, B; Naider, F; Becker, JM (American Chemical Society (ACS), 2008-05-20)
Ste2p is the G protein-coupled receptor (GPCR) for the tridecapeptide pheromone cc factor of Saccharomyces cerevisiae. This receptor- pheromone pair has been used extensively as a paradigm for investigating GPCR structure and function. Expression in yeast harboring a cognate tRNA/aminoacyl-tRNA synthetase pair specifically evolved to incorporate p-benzoyl-L-phenylalanine (Bpa) in response to the amber codon allowed the biosynthesis of Bpa-substituted Ste2p in its native cell. We replaced natural amino acid ...
Aromatic amino acid synthesis performance of bacillus acidocaldarius
Kocabaş, Pınar; Çalık, Pınar; Department of Chemical Engineering (2004)
In this study, the effects of bioprocess operation parameters on aromatic amino acid synthesis performance of Bacillus acidocaldarius were investigated. Firstly, in laboratory scale shake-bioreactors, a defined medium was designed in terms of its carbon and nitrogen sources, to achieve the highest cell concentration. Thereafter, the effects of bioprocess operation parameters, i.e., pH and temperature were investigated; and the optimum medium contained (kg m-3): fructose, 8; (NH4)2HPO4, 5; CaCl2, 0.2; KH2PO4...
İPEK, HALİL; Akdağ, Akın (Informa UK Limited, 2015-08-03)
Chiral sulfoxides are used in asymmetric synthesis and are present in various biologically active compounds. Asymmetric synthesis of the sulfoxides has been performed by chiral metal complexes and non-metals containing peroxide and oxide moieties. In this study, a new metal free method has been developed to oxidize thioanisole into methyl phenyl sulfoxide with easily accessible chiral compounds carrying N-Cl bond. For this purpose, chiral amine and amide bearing reagents were synthesized and chlorinated by ...
Isolation and immunological characterization of theta class glutathione-s-transferase gstt2-2 from bovine liver
İşgör, Sultan Belgin; Çoruh, Nursen; Department of Biochemistry (2004)
The glutathione-S-transferases (GSTs) (EC. are enzymes that participate in cellular detoxification of endogenous as well as foreign electrophilic compounds, function in the cellular detoxification systems and are evolved to protect cells against reactive oxygen metabolites by conjugating the reactive molecules to the nucleophile scavenging tripeptide glutathione (GSH, ?-glu-cys-gly). The GSTs are found in all eukaryotes and prokaryotic systems, in the cytoplasm, on the microsomes, and in the mitoch...
Citation Formats
B. S. Hoşrik, “Benzaldehyde lyase from pseudomonas fluorescens biovar i mediated biotransformation for the synthesis of chiral alpha hydroxy ketones,” M.S. - Master of Science, Middle East Technical University, 2010.