title: Fatty acid unsaturation in the red alga Porphyridium cruentum. Is the methylene interrupted nature of polyunsaturated fatty acids an intrinsic property of the desaturases?
abstract: Polyunsaturated fatty acids (PUFAs) exogenously supplied to the red microalga Porphyridium cruentum were incorporated into cellular lipids. All the C18 PUFAs studied were desaturated by a delta 6-desaturase and all the C20 PUFAs by a delta 5-desaturase. The latter enzyme desaturated even 20:2(11, 14) to 20:3(5, 11, 14) and 20:3(11, 14, 17) to 20:4(5, 11, 14, 17). We infer the existence of several fatty acid desaturases, with different chain length specificities. Furthermore, the introduction of double bonds in a methylene interrupted pattern, at least for alpha-type desaturase such as the delta 5- and delta 6-desaturases, is not an intrinsic property of the enzyme but a consequence of the arrangement of the pre-existing double bonds in the fatty acid substrate.
authors.affiliation: Laboratory for Microalgal Biotechnology, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Israel. cohen@bgumail.bgu.ac.il
authors.forename: Z
authors.initials: Z
authors.lastname: Cohen
authors.forename: D
authors.initials: D
authors.lastname: Shiran
authors.forename: I
authors.initials: I
authors.lastname: Khozin
authors.forename: Y M
authors.initials: YM
authors.lastname: Heimer
mesh_terms: D056890:Eukaryota / Q000201:enzymology / Q000378:metabolism*; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D005227:Fatty Acids / Q000737:chemistry / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis* / Q000737:chemistry; D008055:Lipids / Q000032:analysis / Q000737:chemistry; D013379:Substrate Specificity
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008055:Lipids; D044943:Fatty Acid Desaturases