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Partial Purification and Characterization of an Acid Phosphatase from Papaya
Author(s) -
CARRENO RAPHAEL,
CHAN HARVEY T.
Publication year - 1982
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1982.tb04969.x
Subject(s) - acid phosphatase , enzyme , chemistry , isozyme , phosphatase , substrate (aquarium) , size exclusion chromatography , phosphate , biochemistry , kinetics , chromatography , mole , biology , ecology , physics , quantum mechanics
ABSTRACT A phosphatase in papaya was extracted, partially purified, and characterized. With p ‐nitrophenyl phosphate as substrate, the enzyme had a pH optimum of 6.0, which categorized it as an acid phosphatase, a temperature optimum of 37°C, and a Km of 1.0 mM. Heat inactivation of papaya acid phosphatase was biphasic, and the kinetics of both phases were first order reactions. D values at 60°, 65°, 70°C for the heat resistant phase were 21.0, 11.7, and 4.0 min, respectively. For the heat labile and heat resistant isozymes of papaya acid phosphatase, the activation energies, E a , for thermal inactivation were 60.0 Kcal/mole and 37.8 Kcal/mole, respectively. The apparent molecular weight of the enzyme as determined by gel filtration was 120,000 daltons.