Characterization and histochemical localization of nonspecific esterase from ascocarps of desert truffle (Terfezia claveryi Chatin).
An esterase activity from Terfezia claveryi Chatin ascocarps, a mycorrhizal hypogeous fungus, is described for the first time. The enzyme was partially purified using phase partitioning in Triton X-114 (TX-114), achieving a reduction of 87% in the triglyceride content and the removal of 63% of phenols. The enzyme showed maximum activity toward short-chain p-nitrophenyl esters, and no interfacial activation was observed, indicating that the enzyme responsible for this activity is an esterase and not a lipase. This esterase presented its maximum activity at pH 7.4 and 60 degrees C. The values obtained for Km at pH 7.4 were 0.3 mM for p-nitrophenyl butyrate and 0.6 mM for p-nitrophenyl acetate with catalytic efficiencies (Vmax/Km) of 0.23 and 0.32, respectively. T. claveryi esterase was inhibited by phenylboric acid, indicating that serine residues were involved in the enzyme activity. This activity was localized only in the hypothecium and was absent from the peridium and gleba.
Departamento de Bioquímica y Biología Molecular-A and Departamento de Biología Vegetal, Facultad de Biología Universidad de Murcia, Campus de Espinardo, E-30071 Murcia, Spain. mpg@um.es
Manuela
M
Pérez-Gilabert
Asunción
A
Morte
Rizette
R
Avila-González
Francisco
F
García-Carmona
D001203:Ascomycota / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004950:Esterases / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000378:metabolism; D006651:Histocytochemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013379:Substrate Specificity; D013696:Temperature
D004791:Enzyme Inhibitors; D004950:Esterases