Identification and characterization of phospholipase A₂ inhibitors from the serum of the Japanese rat snake, Elaphe climacophora

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• 作者：Ryoichi Shirai ; Michihisa Toriba ; Kyozo Hayashi ; Kiyoshi Ikeda ; Seiji Inoue
• 关键词：Phospholipase A₂ ; PLA₂ ; Phospholipase A₂ inhibitor ; PLI ; Colubridae ; cDNA sequence
• 刊名：Toxicon
• 出版年：2009
• 出版时间：May 2009
• 年：2009
• 卷：53
• 期：6
• 页码：685-692
• 全文大小：879 K

文摘

Two distinct phospholipase A₂ (PLA₂) inhibitory proteins (PLIs) were purified from the serum of the Japanese rat snake, Elaphe climacophora. The 150-kDa inhibitor, a trimer of a 50-kDa subunit, specifically inhibited the basic PLA₂ purified from the venom of Gloydius brevicaudus, whereas the 120-kDa one composed of two distinct 25-kDa subunits, A and B, inhibited both the acidic and basic PLA₂s of G. brevicaudus. On the basis of their amino acid sequences, these inhibitors were assigned as PLIβ and PLIγ, respectively. A PLIα homolog (PLIα-like protein; PLIα-LP) having an apparent molecular weight of 50-kDa and composed of 15-kDa subunits was also purified from the E. climacophora serum. This homolog was immunoreactive with antibody raised against the G. brevicaudus PLIα, but lacked in the inhibitory activity toward the acidic and basic PLA₂s. The cDNAs encoding PLIα-LP, PLIβ, PLIγ-A, and PLIγ-B were cloned from liver RNA, and their nucleotide sequences were compared with those of other venomous and non-venomous snakes.