Partial Purification and Characterization of Polyphenol Oxidase Isozymes in Banana Bud

Abstract

Polyphenol oxidase was extracted from banana buds in the presences of Triton X-100, isoascorbate, and Polyclar AT, and two isozymes I and II have been separated and partially purified by chromatographies on Butyl Toyopearl 650 and DEAE-cellulose. I and II had different mobility in polyacrylamide gel electrophoresis with optimum pHs of 6.8 and 5.5, respectively. Both enzymes showed the apparent Km values of 0.5 mM for dopamine with substrate inhibitions at its higher concentrations. I and II were inhibited competitively by NaCl with the Ki values of 140 mM and 40 mM, respectively. I and II have a high heat stability, and 88 and 95% of the initial activities were retained after 1-hr incubation at 70°C, respectively. © 1992, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.

Source or Periodical Title

Bioscience, Biotechnology, and Biochemistry

ISSN

9168451

Page

1027-1030

Document Type

Article

Subject

DEAE, diethylaminoethyl, PAGE, polyacrylaimde gel electrophorsis, PPO, polyphenol oxidase

This document is currently not available here.

Share

COinS