title: Fatty acid synthetase from the Harderian gland of guinea pig: biosynthesis of methyl-branched fatty acids.
abstract: Fatty acid synthetase was isolated from guinea pig Harderian gland. This enzyme complex exhibited a unique character as compared with the fatty acid synthetase from the liver of the same animal. The former enzyme produced many odd-numbered and methyl-branched fatty acids in the presence of methylmalonyl-CoA. These fatty acids are characteristic components of the lipid secreted from this gland. The chemical structure of this lipid has been identified as 1-O-alkyl-2,3-diacylglycerol by previous work from this laboratory (Yamazaki, T., Seyama, Y., Otsuka, H., Ogawa, H., & Yamakawa, T. (1981) J. Biochem. 89, 683-691). Apparent Km values (5 X 10(-6) M) for acetyl-CoA and propionyl-CoA were the same, but the Vmax for propionyl-CoA was much higher than that for acetyl-CoA. The pI value of the fatty acid synthetase from Harderian gland was 5.3, and the molecular weight of the enzyme was 9 X 10(5) daltons. The beta-ketoacyl reductase had pro-S stereospecificity and the enoly reductase had pro-R stereospecificity for NADPH. The results presented in this paper indicate that the fatty acid synthetase from guinea pig Harderian gland can produce a set of fatty acids needed for the synthesis of the lipid secreted from this gland, and that the fatty acid synthetase has a characteristic organ specificity.
mesh_terms: D000105:Acetyl Coenzyme A / Q000378:metabolism; D000818:Animals; D064429:Fatty Acid Synthases / Q000302:isolation & purification*; D005227:Fatty Acids / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D006168:Guinea Pigs; D006243:Harderian Gland / Q000201:enzymology*; D007700:Kinetics; D007765:Lacrimal Apparatus / Q000201:enzymology*; D008099:Liver / Q000201:enzymology; D008970:Molecular Weight; D009249:NADP / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D005227:Fatty Acids; D009249:NADP; D000105:Acetyl Coenzyme A; D064429:Fatty Acid Synthases