Abstract
A water tunnel in Candida antarctica lipase B that provides the active site with substrate water is hypothesized. A small, focused library created in order to prevent water from entering the active site through the tunnel was screened for increased transacylation over hydrolysis activity. A single mutant, S47L, in which the inner part of the tunnel was blocked, catalysed the transacylation of vinyl butyrate to 20mM butanol 14 times faster than hydrolysis. The single mutant Q46A, which has a more open outer end of the tunnel, showed an incresed hydrolysis rate and a decreased hydrolysis to transacylation ratio compared to the wild-type lipase. Mutants with a blocked tunnel could be very useful in applications in which hydrolysis is unwanted, such as the acylation of highly hydrophilic compounds in the presence of water.
| Original language | English |
|---|---|
| Journal | ChemBioChem |
| Volume | 11 |
| Issue number | 6 |
| Pages (from-to) | 796-801 |
| Number of pages | 6 |
| ISSN | 1439-4227 |
| DOIs | |
| Publication status | Published - 12 Apr 2010 |
Keywords
- Amino Acid Substitution
- Binding Sites
- Biocatalysis
- Candida
- Catalytic Domain
- Computer Simulation
- Hydrolysis
- Lipase
- Mutagenesis, Site-Directed
- Recombinant Proteins
- Water