Structural and Mechanistic Insights into the Improvement of the Halotolerance of a Marine Microbial Esterase by Increasing Intra- and Interdomain Hydrophobic Interactions.

ABSTRACT: Halotolerant enzymes are beneficial for industrial processes requiring high salt concentrations and low water activity. Most halophilic proteins are evolved to have reduced hydrophobic interactions on the surface and in the hydrophobic cores for their haloadaptation. However, in this study, we improved the halotolerance of a thermolabile esterase, E40, by increasing intraprotein hydrophobic interactions. E40 was quite unstable in buffers containing more than 0.3 M NaCl, and its kcat and substrate affinity were both significantly reduced in 0.5 M NaCl. By introducing hydrophobic residues in loop 1 of the CAP domain and/or α7 of the catalytic domain in E40, we obtained several mutants with improved halotolerance, and the M3 S202W I203F mutant was the most halotolerant. ("M3" represents a mut

SUBMITTER: Li PY 

PROVIDER: S-EPMC5583480 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature