Can the fatty acid selectivity of plant lipases be predicted from the composition of the seed triglyceride?

To address the question can the fatty acid selectivity of plant lipases be predicted from the composition of the seed triglyceride, we have characteri sed the selectivity of lipases from a wide range of oilseeds with diverse f atty acid compositions. For this study, a novel hydrolysis assay using a fu lly randomised oil, was developed. From some seed sources (e.g. Cinnamomum camphora), lipases show high preference for particular fatty acids, whilst from others (e.g. Brassica napus, Theabroma cacao), lipases show no fatty a cid selectivity within the range C8 to C18:3. Using the results, we put for ward a hypothesis that only seeds with > 80% saturated or 'unusual' fatty a cids may contain lipases which exhibit selectivity. It therefore follows th at since the majority of seeds are composed of unsaturated fatty acids, tha t highly selective lipases will be unusual in nature. However lipases from some species of the Cuphea genera show exceptionally high preference for pa rticular fatty acids. For example, lipase from seeds of Cuphea procumbans h as over 20-fold selectivity for C10:0. (C) 1999 Elsevier Science B.V. All r ights reserved.