HYDROPHOBILIZATION OF ESTERASE BY GENETIC COMBINATION WITH POLYPROLINE OR POLYTYROSINE AT THE CARBOXYL-TERMINAL

Citation
Oh. Kwon et al., HYDROPHOBILIZATION OF ESTERASE BY GENETIC COMBINATION WITH POLYPROLINE OR POLYTYROSINE AT THE CARBOXYL-TERMINAL, Biochimica et biophysica acta. Protein structure and molecular enzymology, 1388(1), 1998, pp. 239-246
Citations number
14
Categorie Soggetti
Biology,Biophysics
ISSN journal
01674838
Volume
1388
Issue
1
Year of publication
1998
Pages
239 - 246
Database
ISI
SICI code
0167-4838(1998)1388:1<239:HOEBGC>2.0.ZU;2-N
Abstract
Polyproline (Poly-Pro) that is an amphiphilic polypeptide, or polytyro sine (Poly-Tyr) that is a hydrophobic polypeptide, were connected to t he carboxy terminus of Pseudomonas sp. esterase by the recombinant DNA technique. The hydrophobicity of the esterase was enhanced by the int roduction of Poly-Pro or Poly-Tyr, and also by increasing chain length of the polypeptides. Poly-Tyr increased the hydrophobicity of esteras e more than Poly-Pro. Poly-Tyr induced significant conformational chan ge of fusion esterase, but Poly-Pro did not. Consequently, the introdu ction of Poly-Tyr led to loss of activity of the fusion enzyme to a ne gligible level. On the other hand, the Poly-Pro-fusion-esterase retain ed enzymatic activity and the hydrolytic activity (k(cat)/K-m) of the fusion esterase carrying 40 proline residues (esterase-Pro40) relative to that of the wild-type esterase with the substrates p-nitrophenyl-p ropionate, -pentanoate, and -hexanoate was 1.76, 1.95, and 4.7, respec tively. The results could be explained in terms of easier access of lo ng-chain carboxylate to the fusion esterase compared to the wild-type esterase in aqueous solution. (C) 1998 Elsevier Science B.V. All right s reserved.