[Progress on molecular biology of delta6-fatty acid desaturases]

Polyunsaturated fatty acids (PUFAs) including gamma-linolenic acid are valuable products because of their involvement in several aspects of human health care. GLA has been claimed to play a crucial role in development and prevention of some skin diseases, diabetes, reproductive disorder and others. At present, market demand for most gamma-linolenic acid is growing continually and current sources are inadequate for satisfying this demand due to the significant problems of low productivity, complex and expensive downstream process and unstable quality. Therefore, seeking for alternative sources are demanding. delta6-fatty acid desaturase is the rate-limiting enzyme for the biosynthesis of PUFAs, which catalyses the conversion of linoleic acid and alpha-linolenic acid to gamma-linolenic acid and stearidonic acid respectively. Unfortunately, the structure information on membrane desaturases is scarce because of the technical limitations in obtaining quantities of purified protein and the intrinsic difficulties in obtaining crystals from membrane proteins. With the isolation of the genes coding for delta6-fatty acid desaturase from various organisms, its characteristics will be elucidated gradually. Here we concisely reviewed the recent progress on studies of molecular biology including the cloning of delta6-fatty acid desaturase gene, structure and function, phylogeny and prospects of gene engineering application.