Van Veldhoven P P
Katholieke Universiteit Leuven, Camus Gasthuisberg, Belgium.
J Inherit Metab Dis. 1995;18 Suppl 1:125-34. doi: 10.1007/BF00711435.
Peroxisomal beta-oxidation is involved in the degradation of different fatty acids or fatty acid derivatives including eicosanoids (prostaglandins, leukotrienes, thromboxanes), dicarboxylic fatty acids, very long-chain fatty acids, pristanic acid, bile acid intermediates (di- and trihydroxycoprostanoic acids), and xenobiotics. Separate beta-oxidation systems are probably active inside peroxisomes, each acting on a distinct set of substrates, as suggested by the discovery of multiple acyl-CoA oxidases. Using specific substrates or selective conditions, we can distinguish in rat liver the action of acyl-CoA oxidases (type I and II), a pristanoyl-CoA oxidase and a trihydroxycoprostanoyl-CoA oxidase, and, in in human liver, of acyl-CoA oxidase (type I and II) and a branched-chain acyl-CoA oxidase. When incubated with suitable CoA-esters, these different oxidases can be measured in a similar fashion by following fluorimetrically the dimerization of homovanillic acid, catalysed by peroxidase in the presence of hydrogen peroxide. The optimal assay conditions and possible pitfalls in this type of coupled assay are discussed. This knowledge can be used to reveal the existence of peroxisomal disorders in which only one acyl-CoA oxidase is deficient.
过氧化物酶体β-氧化参与不同脂肪酸或脂肪酸衍生物的降解，包括类二十烷酸（前列腺素、白三烯、血栓素）、二羧酸脂肪酸、极长链脂肪酸、降植烷酸、胆汁酸中间体（二羟基和三羟基粪甾烷酸）以及外源性物质。如多种酰基辅酶A氧化酶的发现所示，过氧化物酶体内可能存在独立的β-氧化系统，每个系统作用于一组不同的底物。使用特定底物或选择性条件，我们可以在大鼠肝脏中区分酰基辅酶A氧化酶（I型和II型）、降植烷酰辅酶A氧化酶和三羟基粪甾烷酰辅酶A氧化酶的作用，在人类肝脏中区分酰基辅酶A氧化酶（I型和II型）和支链酰基辅酶A氧化酶的作用。当与合适的辅酶A酯一起孵育时，通过荧光跟踪在过氧化氢存在下过氧化物酶催化的高香草酸二聚化，可以以类似的方式测量这些不同的氧化酶。讨论了这种类型的偶联测定的最佳测定条件和可能的陷阱。这些知识可用于揭示仅一种酰基辅酶A氧化酶缺乏的过氧化物酶体疾病的存在。
