Biotechnology and Bioengineering vol:78 issue:6 pages:683-691
Pectin methylesterase (PME) was extracted from bananas (cv Cavendish) and purified by affinity chromatography on a CNBr-Sepharose-PME inhibitor (PMEI) column. A single protein and PME activity peak was obtained. For banana PME, a biochemical characterization in terms of molar mass (MM), pl, and kinetic parameters was performed. In a second step, the thermal and high-pressure stability of the enzyme was studied. Isothermal inactivation of purified banana PME could be described by a first-order kinetic model in a temperature range of 65degrees to 72.5degreesC, whereas its isobaric-isothermal inactivation followed a fractional-conversion model. Banana PME was found to be more thermally stable compared with PMEs extracted from orange, tomato, and apple. (C) 2002 Wiley Periodicals, Inc.