Characterization of a cDNA encoding Arabidopsis secretory phospholipase A2-α, an enzyme that generates bioactive lysophospholipids and free fatty acids
Characterization of a cDNA encoding Arabidopsis secretory phospholipase A2-α, an enzyme that generates bioactive lysophospholipids and free fatty acids
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DOI：
10.1016/j.bbalip.2005.08.005
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发表时间：
2005-09-15
影响因子：
4.8
通讯作者：
Palta, JP
中科院分区：
文献类型：
--
作者：
Ryu, SB;Lee, HY;Palta, JP
磷脂酶A(2)s （PLA(2)s）是响应激素和其他外界刺激从膜磷脂中释放溶血磷脂和游离脂肪酸（FFAs）的酶。本文报道了拟南芥PLA2基因AtsPLA(2)- α的克隆和功能表征，该基因是拟南芥中四个分泌PLA2 (2) （sPLA）基因之一。编码的蛋白为148个氨基酸的多肽，预计其氨基端含有一个20个氨基酸的信号肽。预测的AtsPLA(2)- α成熟形态（M-r= 14,169）的比活性约为预处理形态的5倍。与动物sPLA(2)s不同，AtsPLA(2)- α在磷脂水解中对酰基亚油酸比棕榈酸表现出明显的偏好。然而，与一些动物sPLA2s一样，它对磷脂酰乙醇胺的偏好略高于磷脂酰胆碱作为底物。当Ca2+浓度增加到10 mM时，AtsPLA(2)- α的比活性不断增加，且最佳pH范围很宽，在6 ~ 11之间呈双相。在根、茎、叶和花中检测到低水平的AtsPLA(2)- α转录本，但在叶鞘中检测不到。(c) 2005年Elsevier B.V.出版
Phospholipase A(2)s (PLA(2)s) are enzymes that liberate lysophospholipids and free fatty acids (FFAs) from membrane phospholipids in response to hormones and other external stimuli. This report describes the cloning and functional characterization of a PLA2 cDNA from Arabidopsis thaliana, AtsPLA(2)-alpha, which represents one of four secretory PLA(2) (sPLA,) genes in Arabidopsis. The encoded protein is 148 amino acid polypeptide and is predicted to contain a 20-amino acid signal peptide at its amino terminus. The predicted mature form (M-r= 14,169) of AtsPLA(2)-alpha exhibited approximately 5 times the specific activity of its pre-processed form. Different from animal sPLA(2)s, AtsPLA(2)-alpha showed a significant preference for the acyl group linoleic acid over palmitic acid in phospholipid hydrolysis. Like some animal sPLA2s, however, it has a slight preference for phosphatidylethanolamine over phosphatidylcholine as the substrate. The specific activity of AtsPLA(2)-alpha continuously increased as the Ca2+ concentration was increased to 10 mM, and the optimal pH range was very broad and biphasic between 6 and 11. AtsPLA(2)-alpha transcript was detected at low levels in roots, stems, leaves, and flowers but not in siliques. (c) 2005 Published by Elsevier B.V.