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Inhibition of tomato pectin methylesterase by partially purified kiwi pectin methylesterase inhibitor protein
Author(s) -
MARQUIS HÉLÈNE,
BUCHELI PETER
Publication year - 1994
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.1994.tb02052.x
Subject(s) - pectinesterase , chemistry , pectin , sephadex , sepharose , biochemistry , chromatography , actinidia chinensis , protease , enzyme , biology , botany , pectinase
The inhibition of tomato pectin methylesterase (PME) by a recently discovered kiwi pectin methylesterase inhibitor (PMEI) is described. PME was consequently purified by CM Sephadex C‐50, Concanavalin A‐Sepharose 4 B and Mono S chromatography, and PMEI by Q‐Sepharose and Sephacryl S‐200 chromatography. Inhibition of tomato PME activity under optimal conditions (0.125 m NaCl, pH 7.5) by partially purified kiwi PMEI (MW of 27 kD, pI ≥ 3.67) was independent of the PMEI/PME ratio between 36 and 61% of the maximal uninhibited activity. the non‐competitive inhibition observed was optimal in the pH range of 5 to 7. PMEI was inactivated by heating to 120°C, and showed actinidin‐like activity towards N‐α‐benzyloxycarbonyl‐L‐lysine p ‐nitrophenyl ester (CBZ‐lys‐ONp) and azocasein which was partially inhibited by the protease inhibitor leupeptin.