Solubilization of Acyl‐CoA elongases from developing rapeseed (Brassica napus L.)

Acyl‐CoA elongases are important in producing high‐erucic acid rapeseed. The effects of Triton X‐100, N ‐octyl‐β‐D‐glucopyranoside and deoxycholate on the C18:1‐CoA and C20:1‐CoA elongase(s) have been studied by using a 15,000 × g pellet from developing rapeseed. The synthesis of very long chain monounsaturated fatty acids (VLCMFA) and, in particular, that of erucic acid were stimulated by Triton X‐100, whatever the substrate used. In the presence of N ‐octyl‐β‐D‐glucopyranoside, the elongase activity was practically unchanged, whereas deoxycholate strongly inhibited VLCMFA synthesis. Triton X‐100 was chosen for the solubilization, at an optimal Triton X‐100/protein (w/w) ratio of 2.5. Acyl‐CoAs were the major products synthesized by the solubilized acyl‐CoA elongase(s). The analysis of the reaction intermediates showed that the entire elongation complex has been solubilized and was still functional.