In mammalian species, the Fatty Acid Desaturase (FADS) gene cluster includes FADS1 (∆5-desaturase), FADS2 (∆6-desaturase), and a third gene member, named FADS3. According to its high degree of nucleotide sequence homology with both FADS1and FADS2, FADS3 was promptly suspected by researchers in the field to code for a new mammalian membrane-bound fatty acid desaturase. However, no catalytic activity was attributed to the FADS3 protein for a decade, until the rat FADS3 protein was shown in vitro to be able to catalyze the unexpected ∆13-desaturation of trans-vaccenic acid, producing the trans11,cis13-conjugated linoleic acid isomer. This review summarizes the recent investigations establishing the FADS3 enzyme as a reliable mammalian trans-vaccenate ∆13-desaturase in vivo and tries to identify further unresolved issues that need to be addressed.

中文翻译：

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脂肪酸去饱和酶 3 (FADS3) 是一种特定的反刍动物反式五烯酸的Δ13-去饱和酶

在哺乳动物物种中，脂肪酸去饱和酶 (FADS) 基因簇包括 FADS1（Δ5-去饱和酶）、FADS2（Δ6-去饱和酶）和第三个基因成员，称为 FADS3。由于其与FADS1和FADS2的核苷酸序列高度同源，FADS3迅速被该领域的研究人员怀疑编码一种新的哺乳动物膜结合脂肪酸去饱和酶。然而，十年来，FADS3 蛋白没有催化活性，直到大鼠 FADS3 蛋白在体外被证明能够催化出乎意料的反式 13 去饱和，产生反式 11，顺式 13 共轭亚油酸异构体。本综述总结了最近将 FADS3 酶确立为一种可靠的哺乳动物体内跨疫苗酸 Δ13-去饱和酶的研究，并试图确定需要解决的进一步未解决的问题。