Enzyme system for the production of signal trunsmitters in human platelets

用于在人血小板中产生信号传递体的酶系统

• 批准号: 02453126
• 负责人: KITO Makoto
• 金额: $ 3.33万
• 依托单位: Kyoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-02453126/
• 关键词: Human platelets; Phospholipase C; Diacylglycerol lipase; Arachidonic acid; Phosphatidylinositol-4, 5-bisphosphate; ジアシルグリセロ-ル; ホスファチジルイノシト-ル

In collagen-activated human platelets, elevation of cytosolic Ca^<2+> 2 level was not caused by collagen itself, but by thromboxane A_2, Of Which precursor arachidonate was produced via collagen-induced inositot lipid metabolism. The metabolism was catalyzed by cooperation of inositol lipid-spercific phospholipase C, diacylglycerol lipase and monoacylglycerol lipase.Two types of cytosolic phospholipase C(PLC) specific for phosphoinositides were purified from human platelets. The molecular masses of the purified en2ymes were 440 ind 290 KDa. These en2Ymes were concluded to be respectively a trimer and a dimer of homologous 146 KDa polypeptides. The 146 KDa polypeptide may be an immunologically novel isozyme among the 140-150 KDa PLC isozymes. Both enzymes hydrolyzed phosphatidylinositol and phosphatidylinositol-4, 5-bisphosphate in a Ca^<2+> 2-dependent manner.Diicylglycerof lipase was partially purified from human platelet membranes. The enzyme catalyzed the reaction around neutral pH even in the absence of Ca^<2+>.Purification and properties of human platelet monoacylglycerof lipase will be examined in near future.

在胶原激活的人血小板中，胞浆Ca^2+水平的升高不是胶原本身引起的，而是血栓素A_2引起的，血栓素A_2的前体花生四烯酸是通过胶原诱导的肌醇脂代谢产生的。从人血小板中分离纯化了两种胞浆型磷脂酶C（PLC），分别为肌醇磷脂特异性磷脂酶C、甘油二酯脂肪酶和甘油单酯脂肪酶。纯化酶的分子量为440和290 KDa。这些en 2 Ymes分别是同源146 KDa多肽的三聚体和二聚体。146 KDa多肽可能是140-150 KDa PLC同工酶中一种新的免疫学同工酶。这两种酶都以Ca^2+依赖的方式水解磷脂酰肌醇和磷脂酰肌醇-4，5-二磷酸。该酶在无Ca^<2+存在的情况下也能在中性pH下催化反应。

项目成果

H.Takamura: "A Highly Sensitive Method for Quantitative Andlysis of Phospholipid Molecular Species by HighーPerformance Liquid Chromatography" Journal of Biochemistry. 109. 436-439 (1991)

H. Takamura：“通过高效液相色谱法定量分析磷脂分子的高灵敏度方法”《生物化学杂志》109. 436-439 (1991)

T.Moriyama: "Purification of Polymeric Phospholipase Cs from Human Platelets" Journal of Biochemistry. 108. 414-419 (1990)

T.Moriyama：“从人血小板中纯化聚合磷脂酶 Cs”生物化学杂志。

H.Takamura: "Phospholipid molecular species in human umbilical artery and vein endothelial cells" Jouranal of Lipid Research. 31. 709-717 (1990)

H.Takamura：“人脐动脉和静脉内皮细胞中的磷脂分子种类”脂质研究杂志。

鬼頭 誠: "ヒト血小板の活性化とリン脂質変動ー分子種分析による解析ー" 蛋白質 核酸 酵素. 36. 209-215 (1991)

Makoto Kito：“人血小板中的活化和磷脂波动 - 通过分子种类分析进行分析”蛋白质核酸酶。 36. 209-215 (1991)

T. Moriyama, H. Narita, M. Oki, T. Matsuura and M. Kito: "Purification of Polymeric Phospholipase Cs from Human Platelets" Journal of Biochemistry. 108. 414-419 (1991)

T. Moriyama、H. Narita、M. Oki、T. Matsuura 和 M. Kito：“从人血小板中纯化聚合磷脂酶 C”《生物化学杂志》。