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Title: Para-nitrobenzyl esterases with enhanced activity in aqueous and nonaqueous media

A method is disclosed for isolating and identifying modified para-nitrobenzyl esterases. These enzymes exhibit improved stability and/or esterase hydrolysis activity toward selected substrates and under selected reaction conditions relative to the unmodified para-nitrobenzyl esterase. The method involves preparing a library of modified para-nitrobenzyl esterase nucleic acid segments (genes) which have nucleotide sequences that differ from the nucleic acid segment which encodes for unmodified para-nitrobenzyl esterase. The library of modified para-nitrobenzyl nucleic acid segments is expressed to provide a plurality of modified enzymes. The clones expressing modified enzymes are then screened to identify which enzymes have improved esterase activity by measuring the ability of the enzymes to hydrolyze the selected substrate under the selected reaction conditions. Specific modified para-nitrobenzyl esterases are disclosed which have improved stability and/or ester hydrolysis activity in aqueous or aqueous-organic media relative to the stability and/or ester hydrolysis activity of unmodified naturally occurring para-nitrobenzyl esterase. 43 figs.
Authors:
;
Publication Date:
OSTI Identifier:
644378
Report Number(s):
US 5,741,691/A/
PAN: US patent application 8-589,893; CNN: Grant N00014-91-J-1397
DOE Contract Number:
FG02-93CH10578
Resource Type:
Patent
Resource Relation:
Other Information: PBD: 21 Apr 1998
Research Org:
California Institute of Technology
Sponsoring Org:
USDOE, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; BIODEGRADATION; NITRO COMPOUNDS; ESTERASES; ENZYMATIC HYDROLYSIS; ENZYME ACTIVITY; REMEDIAL ACTION