LONG-CHAIN SATURATED FATTY-ACIDS CAN BE ALPHA-OXIDIZED BY A PURIFIED ENZYME (M(R), 240000) IN CUCUMBER (CUCUMIS-SATIVUS)

An enzyme (M(r) 240000) with high fatty acid alpha-oxidation activity has been purified from the fruit of cucumber (Cucumis sativus). The sp ecific alpha-oxidation activity in the purified fraction was 370 nmol/ min per mg protein determined as liberation of (CO2)-C-14 from [1-C-14 ]palmitic acid. alpha-Oxidation activity was observed both in the 1200 0 X g pellet and 150 000 X g pellet by differential fractionation of c ucumber homogenate. The enzyme was purified about 220-fold to near hom ogeneity from a 12000 X g fraction by solubilisation with Triton X-100 R, ammonium sulphate precipitation, hydrophobic interaction and anion- exchange chromatographies and Superose 12 gel filtration. The molecula r mass of the native enzyme was 240 000, and the major subunit molecul ar mass of 40 000 indicated an oligomeric structure.