Penicillin G acylase containing one or a plurality of point mutation

Abstract

The present invention relates to a new penicillin G acylase mutant, nucleic acid for encoding the mutant, a related expression vector, host cells, and a use of the mutant in amoxicillin synthesis.

Description

technical field [0001] The invention relates to the field of medicine production, in particular to the production of beta-lactam antibiotics and enzymes used for production thereof, more specifically to penicillin G acylase and its application in the production of beta-lactam antibiotics. Background technique [0002] β-lactam antibiotics are the most important class of antibiotics in clinical application (including penicillins and cephalosporins, etc.), the penicillane or cephem contained in their molecules can destroy the cell wall of bacteria and reproduce in bacterial cells play a bactericidal role. Naturally occurring β-lactam antibiotics have disadvantages such as narrow antibacterial spectrum, acid resistance, easy drug resistance, and easy allergic reactions. These shortcomings have prompted the development of semi-synthetic penicillins and semi-synthetic cephalosporins. [0003] Penicillin G acylase (penicillin G acylase, PGA, EC 3.5.1.11)) can hydrolyze penicillin...

AI Technical Summary

Problems solved by technology

[0006] In addition, the international patent application WO96 / 05318 changes the specificity and synthesis / hydrolysis ratio of PGA by mutating one or more amino acids of the substrate binding site; The mutation of the β56 or β177 amino acid, especially the mutant βF 24A, has a significant increase in the production of penicillins and cephalosporins; while in WO03 / 055998, although the mutants αR145L, αR145C, and αR145K have higher synthesis / hydrolysis ratio, but the synthetic activity is greatly reduced, and the mutant of BmPGA reported by Chinese patent CN101177688 also shows similar results

[0007] Although researchers have isolated, purified, cloned and expressed many naturally occurring PGAs and modified them, these PGAs are still unsatisfactory in many aspects, such as inefficient maturation into active enzymes, low synthetic activity or synthesis / hydrolysis (S / H) The ratio is low, and the by-products generated are many, etc.

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