Extraction, Purification, and Characterization of Olive (Olea europaea L., cv. Chemlal) Polyphenol Oxidase.
J Agric Food Chem
; 72(6): 3099-3112, 2024 Feb 14.
Article
em En
| MEDLINE
| ID: mdl-38291573
ABSTRACT
Among fruits susceptible to enzymatic browning, olive polyphenol oxidase (OePPO) stood out as being unisolated from a natural source until this study, wherein we successfully purified and characterized the enzyme. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of heated and nonheated OePPO revealed distinct molecular weights of 35 and 54 kDa, respectively, indicative of its oligomeric nature comprising active and C-terminal subunits. OePPO displayed latency, fully activating with 5 mM SDS under optimal conditions of pH 7.5 and 15 °C. The enzyme demonstrated monophenolase activity and showcased the highest efficiency toward hydroxytyrosol. Despite its low optimal temperature, OePPO exhibited high thermal resistance, maintaining stability up to 90 °C. However, beyond this threshold, the oligomeric enzyme disassociated, yielding a denatured main subunit and C-terminal fragments. Six OePPO genes were found in the fruits. Tryptic digestion identified the enzyme as mature OePPO1 (INSDC OY733096), while mass spectrometry detected the active form mass alongside several C-terminal fragments, revealing potential cleavage sites (Gly407, Tyr408).
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Texto completo:
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Bases de dados:
MEDLINE
Assunto principal:
Olea
Idioma:
En
Revista:
J Agric Food Chem
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Áustria