Mukherji Mridul, Schofield Christopher J, Wierzbicki Anthony S, Jansen Gerbert A, Wanders Ronald J A, Lloyd Matthew D
The Oxford Centre for Molecular Sciences & The Dyson Perrins Laboratory, South Parks Road, Oxford OX1 3QY, UK.
Prog Lipid Res. 2003 Sep;42(5):359-76. doi: 10.1016/s0163-7827(03)00016-x.
Mammalian metabolism of some lipids including 3-methyl and 2-methyl branched-chain fatty acids occurs within peroxisomes. Such lipids, including phytanic and pristanic acids, are commonly found within the human diet and may be derived from chlorophyll in plant extracts. Due to the presence of a methyl group at its beta-carbon, the well-characterised beta-oxidation pathway cannot degrade phytanic acid. Instead its alpha-methylene group is oxidatively excised to give pristanic acid, which can be metabolised by the beta-oxidation pathway. Many defects in the alpha-oxidation pathway result in an accumulation of phytanic acid, leading to neurological distress, deterioration of vision, deafness, loss of coordination and eventual death. Details of the alpha-oxidation pathway have only recently been elucidated, and considerable progress has been made in understanding the detailed enzymology of one of the oxidative steps within this pathway. This review summarises these recent advances and considers the roles and likely mechanisms of the enzymes within the alpha-oxidation pathway.
包括3-甲基和2-甲基支链脂肪酸在内的一些脂质的哺乳动物代谢发生在过氧化物酶体中。这类脂质，包括植烷酸和降植烷酸，常见于人类饮食中，可能来源于植物提取物中的叶绿素。由于植烷酸的β-碳上存在一个甲基，已被充分研究的β-氧化途径无法降解植烷酸。相反，其α-亚甲基被氧化切除生成降植烷酸，而降植烷酸可通过β-氧化途径进行代谢。α-氧化途径中的许多缺陷会导致植烷酸积累，进而导致神经功能障碍、视力减退、耳聋、协调能力丧失，最终死亡。α-氧化途径的细节直到最近才得以阐明，并且在理解该途径内一个氧化步骤的详细酶学方面已经取得了相当大的进展。这篇综述总结了这些最新进展，并探讨了α-氧化途径中酶的作用和可能的机制。
