Para-nitrobenzyl esterases with enhanced activity in aqueous and nonaqueous media
A method is disclosed for isolating and identifying modified para-nitrobenzyl esterases which 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.
- Research Organization:
- California Institute of Technology (CalTech), Pasadena, CA (United States)
- Sponsoring Organization:
- USN; USDOE, Washington, DC (United States); Department of the Navy, Washington, DC (United States)
- DOE Contract Number:
- FG02-93CH10578
- Assignee:
- California Inst. of Tech., Pasadena, CA (United States)
- Patent Number(s):
- US 5906930; A
- Application Number:
- CNN: N00014-91-J-1397; PPN: US 9-020991
- OSTI ID:
- 6479844
- Resource Relation:
- Patent File Date: 9 Feb 1998
- Country of Publication:
- United States
- Language:
- English
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Para-nitrobenzyl esterases with enhanced activity in aqueous and nonaqueous media
Para-nitrobenzyl esterases with enhanced activity in aqueous and nonaqueous media