บทคัดย่องานวิจัย

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Extraction, partial purification and characterization of 1-aminocyclopropane-1-carboxylic acid oxidase from apple fruit.

Kuai, J. and Dilley, D. R.

Postharvest Biology and Technology Year: 1992 Vol: 1 Issue: 3 Pages: 203-211.

1992

บทคัดย่อ

Extraction, partial purification and characterization of 1-aminocyclopropane-1-carboxylic acid oxidase from apple fruit.

ACC oxidase (ethylene-forming enzyme) was extracted, partially purified and characterized from Golden Delicious apple fruit cortical tissue. The presence of 5% w/v polyvinylpolypyrrolidone (PVPP) was necessary in the extraction medium to obtain an active enzyme from the fruit tissue. The specific activity was 40-100 nl ethylene h-1 mg-1 protein in the crude extract; polyethylene glycol fractionation followed by calcium phosphate gel adsorption resulted in ca. 10-fold purification. Enzyme activity was retained at -20 deg C when the enzyme was stored in 30% glycerol. Ascorbate and Fe2+ were not essential in the extraction medium. Apple ACC oxidase had a Km for ACC of 6.4 micro M, a Km for O2 of 0.4% and a pH optimum of 7.2 in Tris-Mes buffer and 7.6 in phosphate buffer. The enzyme was stereospecific for substrate; it converted ( plus or minus )allocoronamic acid to 1-butene while ( plus or minus )coronamic acid was 10-fold less effective as a substrate.