Biosynthesis of anandamide and N-palmitoylethanolamine by sequential actions of phospholipase A2 and lysophospholipase D
Biosynthesis of anandamide and N-palmitoylethanolamine by sequential actions of phospholipase A2 and lysophospholipase D
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DOI：
10.1042/bj20040031
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发表时间：
2004-06-15
影响因子：
4.1
通讯作者：
Ueda, N
中科院分区：
文献类型：
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作者：
Sun, YX;Tsuboi, K;Ueda, N
N-酰基磷脂酰乙醇胺(N-acyl-phatidyleetholamine，N-acyl-POE)通过磷脂酶D(PLD)从N-酰基磷脂酰乙醇胺(N-acyl-POE)中直接释放出来，形成具有生物活性的长链NAE(N-酰基乙醇胺)。然而，先前也有人提出了N-酰基-PE可能存在的两步途径，包括(1)由聚乳酸(1)/聚乳酸(2)酶(S)将N-酰基-PE水解为N-酰基-溶质PE(2)通过溶血磷脂酶D(S)从N-酰基-溶体PE中释放NAE。在目前的研究中，我们第一次报告了负责这一途径的酶的特征。N-棕榈酰-PE的聚乳酸(1)/聚乳酸(2)活性在大鼠不同组织中均有表达，其中胃的活性最高。该胃酶被鉴定为IB组Spla(2)(分泌型聚乳酸(2))，其产物为N-酰基-1-酰基-溶解PE。重组Spla的IB、IIA和V群对N-Palmitoyi-PE也有激活作用，而X组Spla(2)和胞浆PLa(2)α无活性。此外，我们还发现，从N-棕榈酰基-溶菌素合成N-棕榈酰乙醇胺的溶菌体PLD活性在大鼠组织中分布广泛，在脑和睾丸中的活性较高。根据几条酶学证据，溶酶PLD酶可能与已知的N-酰基-PE水解酶PLD不同。Spla(2)-IB呈剂量依赖性地促进脑匀浆中N-Palmitoyi-PE合成N-Palmityl-乙醇胺，表现出溶血磷脂酶D活性。N-花生四烯醇酰-PE和N-花生四烯酰基-溶解PE分别是制备SPLA(2)-IB和溶解PLD的良好底物。这些结果表明，PLA2和溶解PLD的顺序作用可能构成了NAE的另一种生物合成途径，包括ANANDAME。
Anandamide (an endocannabinoid) and other bioactive long-chain NAEs (N-acylethanolamines) are formed by direct release from N-acyl-PE (N-acyl-phosphatidylethanolamine) by a PLD (phospholipase D). However, the possible presence of a two-step pathway from N-acyl-PE has also been suggested previously, which comprises (1) the hydrolysis of N-acyl-PE to N-acyl-lysoPE by PLA(1)/PLA(2) enzyme(s) and (2) the release of NAEs from N-acyllysoPE by lysoPLD (lysophospholipase D) enzyme(s). In the present study we report for the first time the characterization of enzymes responsible for this pathway. The PLA(1)/PLA(2) activity for N-palmitoyl-PE was found in various rat tissues, with the highest activity in the stomach. This stomach enzyme was identified as group IB sPLA(2) (secretory PLA(2)) and its product was determined as N-acyl-1-acyl-lysoPE. Recombinant group IB, IIA and V of sPLA(2)S were also active with N-palmitoyi-PE, whereas group X sPLA(2) and cytosolic PLA(2)alpha were inactive. In addition, we found wide distribution of lysoPLD activity generating N-palmitoylethanol amine from N-palmitoyl-lysoPE in rat tissues, with higher activities in the brain and testis. Based on several lines of enzymological evidence, the lysoPLD enzyme could be distinct from the known N-acyl-PE-hydrolysing PLD. sPLA(2)-IB dose dependently enhanced the production of N-palmitoylethanolamine from N-palmitoyi-PE in the brain homogenate showing the lysoPLD activity. N-Arachidonoyl-PE and N-arachidonoyl-lysoPE as anandamide precursors were also good substrates of sPLA(2)-IB and the lysoPLD respectively. These results suggest that the sequential actions of PLA2 and lysoPLD may constitute another biosynthetic pathway for NAEs, including anandamide.