FATTY-ACID ALPHA-OXIDATION OF TETRADECYLTHIOACETIC ACID AND TETRADECYLTHIOPROPIONIC ACID IN CUCUMBER (CUCUMIS-SATIVUS)

Fatty acid alpha-oxidation in cucumber (Cucumis sativus) involves enzy matic conversion of long-chain C-n-fatty acids to the C(n-1)-aldehyde and CO2. However, the mechanism of this process is not well understood . In this study, the alpha-oxidation of the fatty acid analogues tetra decylthioacetic acid (TTA) and tetradecylthiopropionic acid (TTP) with a sulphur atom substituting the methylene group in positions 3 and 4, respectively, was investigated and compared to palmitic acid. Both [1 -C-14]TTA and [1-C-14]TTP could be alpha-oxidised in the cucumber subc ellular 150 000 x g(max) fraction. [1-C-14]TTP was an even better subs trate compared to the natural palmitic acid, while [1-C-14]TTA was alp ha-oxidised to a lower extent. [2-C-14]TTA revealed no (CO2)-C-14, ind icating that only one cycle of alpha-oxidation occurred. TTA was an in hibitor of the palmitic acid a-oxidation, and the inhibitory effects w ere examined. (C) 1998 Published by Elsevier Science B.V. All rights r eserved.