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Characterization of polyphenol oxidase and peroxidase from peach mesocarp ( Prunus persica L. cv. Babygold)
Author(s) -
JiménezAtiénzar Mercedes,
Pedreño María A,
Caballero Nuria,
Cabanes Juana,
GarcíaCarmona Francisco
Publication year - 2007
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2886
Subject(s) - polyphenol oxidase , peroxidase , chlorogenic acid , browning , chemistry , point of delivery , polyacrylamide gel electrophoresis , isoelectric focusing , gel electrophoresis , catechol oxidase , molecular mass , biochemistry , enzyme , chromatography , botany , biology
Abstract The two enzymes involved in enzymatic browning reactions—polyphenol oxidase (PPO) and peroxidase (POD)—were extracted from peach fruit mesocarp. PPO was mainly located in the membrane fraction and was in its latent state. However, POD activity was found in the soluble fraction. The kinetic characterization of PPO and POD was carried out with a natural substrate (chlorogenic acid) and with a non‐physiological substrate. Under native isoelectric focusing (IEF), several PPO isoenzymes were present in the pH range 5.4–5.8. A partially denaturing sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS‐PAGE) showed the presence of two active bands with apparent molecular masses of 49 and 50 kDa. A totally denaturing SDS‐PAGE indicated the presence of a single polypeptide with a molecular mass of 60 kDa, as revealed by western blot. POD was also analyzed by IEF, showing the presence of two strongly basic isoenzymes, which were resolved by cationic native PAGE into two different bands. Copyright © 2007 Society of Chemical Industry