Six D A, Dennis E A
Department of Chemistry and Biochemistry, MC 0601, Revelle College and School of Medicine, University of California, San Diego, La Jolla, CA 92093-0601, USA.
Biochim Biophys Acta. 2000 Oct 31;1488(1-2):1-19. doi: 10.1016/s1388-1981(00)00105-0.
The phospholipase A(2) (PLA(2)) superfamily consists of a broad range of enzymes defined by their ability to catalyze the hydrolysis of the middle (sn-2) ester bond of substrate phospholipids. The hydrolysis products of this reaction, free fatty acid and lysophospholipid, have many important downstream roles, and are derived from the activity of a diverse and growing superfamily of PLA(2) enzymes. This review updates the classification of the various PLA(2)'s now described in the literature. Four criteria have been employed to classify these proteins into one of the 11 Groups (I-XI) of PLA(2)'s. First, the enzyme must catalyze the hydrolysis of the sn-2 ester bond of a natural phospholipid substrate, such as long fatty acid chain phospholipids, platelet activating factor, or short fatty acid chain oxidized phospholipids. Second, the complete amino acid sequence of the mature protein must be known. Third, each PLA(2) Group should include all of those enzymes that have readily identifiable sequence homology. If more than one homologous PLA(2) gene exists within a species, then each paralog should be assigned a Subgroup letter, as in the case of Groups IVA, IVB, and IVC PLA(2). Homologs from different species should be classified within the same Subgroup wherever such assignments are possible as is the case with zebra fish and human Group IVA PLA(2) orthologs. The current classification scheme does allow for historical exceptions of the highly homologous Groups I, II, V, and X PLA(2)'s. Fourth, catalytically active splice variants of the same gene are classified as the same Group and Subgroup, but distinguished using Arabic numbers, such as for Group VIA-1 PLA(2) and VIA-2 PLA(2)'s. These four criteria have led to the expansion or realignment of Groups VI, VII and VIII, as well as the addition of Group XI PLA(2) from plants.
磷脂酶A2（PLA2）超家族由一系列广泛的酶组成，这些酶的定义是它们能够催化底物磷脂中间（sn-2）酯键的水解。该反应的水解产物，即游离脂肪酸和溶血磷脂，具有许多重要的下游作用，并且源自一个多样且不断增长的PLA2酶超家族的活性。本综述更新了目前文献中描述的各种PLA2的分类。已采用四个标准将这些蛋白质分类为PLA2的11个组（I-XI）之一。首先，该酶必须催化天然磷脂底物（如长脂肪酸链磷脂、血小板活化因子或短脂肪酸链氧化磷脂）的sn-2酯键的水解。其次，必须知道成熟蛋白质的完整氨基酸序列。第三，每个PLA2组应包括所有具有易于识别的序列同源性的酶。如果一个物种内存在多个同源PLA2基因，那么每个旁系同源物应分配一个亚组字母，如IV A、IV B和IV C组PLA2的情况。只要有可能，来自不同物种的同源物应分类在同一亚组中，如斑马鱼和人类IV A组PLA2直系同源物的情况。当前的分类方案确实允许高度同源的I、II、V和X组PLA2有历史例外情况。第四，同一基因的催化活性剪接变体分类为同一组和亚组，但使用阿拉伯数字区分，如VI A-1组PLA2和VI A-2组PLA2。这四个标准导致了VI、VII和VIII组的扩展或重新排列，以及从植物中添加了XI组PLA2。
