Environmental Factors Modulating the Stability and Enzymatic Activity of the Petrotoga mobilis Esterase (PmEst)

Autor(es)

Lopes, Jose L. S. ^[1] ; Yoneda, Juliana S. ^{[2, 1]} ; Martins, Julia M. ^[3] ; DeMarco, Ricardo ^[3] ; Jameson, David M. ^[4] ; Castro, Aline M. ^[5] ; Bossolan, Nelma R. S. ^[3] ; Wallace, B. A. ^[2] ; Araujo, Ana P. U. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Fis, CP 20516, BR-01498 Sao Paulo - Brazil

^[2] Univ London, Birkbeck Coll, Inst Struct & Mol Biol, London - England

^[3] Univ Sao Paulo, Inst Fis Sao Carlos, Sao Carlos, SP - Brazil

^[4] Univ Hawaii Manoa, Dept Cell & Mol Biol, Honolulu, HI 96822 - USA

^[5] Ctr Res & Dev, Div Biotechnol, Petrobras - Brazil

• Tipo de documento: Artigo Científico
• Fonte: PLoS One; v. 11, n. 6 JUN 28 2016.
• Citações Web of Science: 4

Resumo

Enzymes isolated from thermophilic organisms found in oil reservoirs can find applications in many fields, including the oleochemical, pharmaceutical, bioenergy, and food/dairy industries. In this study, in silico identification and recombinant production of an esterase from the extremophile bacteria Petrotoga mobilis (designated PmEst) were performed. Then biochemical, bioinformatics and structural characterizations were undertaken using a combination of synchrotron radiation circular dichroism (SRCD) and fluorescence spectroscopies to correlate PmEst stability and hydrolytic activity on different substrates. The enzyme presented a high Michaelis-Menten constant (K-M 0.16 mM) and optimum activity at similar to 55 degrees C for p-nitrophenyl butyrate. The secondary structure of PmEst was preserved at acid pH, but not under alkaline conditions. PmEst was unfolded at high concentrations of urea or guanidine through apparently different mechanisms. The esterase activity of PmEst was preserved in the presence of ethanol or propanol and its melting temperature increased similar to 8 degrees C in the presence of these organic solvents. PmEst is a mesophilic esterase with substrate preference towards short-to medium-length acyl chains. The SRCD data of PmEst is in agreement with the prediction of an alpha/beta protein, which leads us to assume that it displays a typical fold of esterases from this family. The increased enzyme stability in organic solvents may enable novel applications for its use in synthetic biology. Taken together, our results demonstrate features of the PmEst enzyme that indicate it may be suitable for applications in industrial processes, particularly, when the use of polar organic solvents is required. (AU)

• Processo FAPESP: 15/50347-2 - Estudos biofísicos da estrutura/função de peptídeos antimicrobianos e enzimas isoladas de organismos extremófilos
• Beneficiário: Ana Paula Ulian de Araujo
• Modalidade de apoio: Auxílio à Pesquisa - Regular