Serine Phospholipid-specific Phospholipase A That Is Secreted from Activated Platelets
Serine Phospholipid-specific Phospholipase A That Is Secreted from Activated Platelets
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活化血小板分泌的丝氨酸磷脂特异性磷脂酶 A
DOI：
10.1074/jbc.272.4.2192
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
Keizō Inoue
中科院分区：
文献类型：
--
作者：
Takuji Sato;J. Aoki;Y. Nagai;N. Dohmae;K. Takio;T. Doi;H. Arai;Keizō Inoue
大鼠血小板在刺激时会分泌两种类型的磷脂酶，一种是II型磷脂酶A2，另一种是丝氨酸选择性磷脂酶A。从激活的大鼠血小板胞外培养上清液中纯化得到的最终产物，在SDS-聚丙烯酰胺凝胶电泳法上显示一条55 kDa的蛋白条带。该酶的抑制剂氟磷酸二异丙酯标记了55 kDa的蛋白，表明该多肽具有活性丝氨酸残基。从大鼠巨核细胞的cDNA文库中克隆了该酶的cDNA。预测的456个氨基酸序列包含一个短的N-末端信号序列和一个GXSXG序列，该序列是丝氨酸酯酶活性丝氨酸残基的基序。氨基酸序列同源性分析表明，该酶与哺乳动物脂肪酶(脂蛋白脂肪酶、肝脂酶和胰腺脂肪酶)的同源性约为30%。可能形成“脂肪酶三联体”的丝氨酸、组氨酸和天冬氨酸周围的区域在这些酶中高度保守。利用杆状病毒系统在Sf9昆虫细胞中表达的重组蛋白能降解溶血磷脂酰丝氨酸和磷脂酰丝氨酸sn-1位的脂肪酰基残基，但对磷脂酰胆碱、磷脂酰乙醇胺、磷脂酰肌醇、磷脂酸和甘油三酯没有明显的降解作用。目前的酶，命名为磷脂酰丝氨酸-磷脂酶A1，是第一个专门降解sn-1位的磷脂酶，对底物具有严格的头基专一性。
Rat platelets secrete two types of phospholipases upon stimulation; one is type II phospholipase A2 and the other is serine-phospholipid-selective phospholipase A. In the current study we purified serine-phospholipid-selective phospholipase A and cloned its cDNA. The final preparation, purified from extracellular medium of activated rat platelets, gave a 55-kDa protein band on SDS-polyacrylamide gel electrophoresis. [3H]Diisopropyl fluorophosphate, an inhibitor of the enzyme, labeled the 55-kDa protein, suggesting that this polypeptide possesses active serine residues. The cDNA for the enzyme was cloned from a rat megakaryocyte cDNA library. The predicted 456-amino acid sequence contains a putative short N-terminal signal sequence and a GXSXG sequence, which is a motif of an active serine residue of serine esterase. Amino acid sequence homology analysis revealed that the enzyme shares about 30% homology with mammalian lipases (lipoprotein lipase, hepatic lipase, and pancreatic lipase). Regions surrounding the putative active serine, histidine, and aspartic acid, which may form a “lipase triad,” were highly conserved among these enzymes. The recombinant protein, which we expressed in Sf9 insect cells using the baculovirus system, hydrolyzed a fatty acyl residue at the sn-1 position of lysophosphatidylserine and phosphatidylserine, but did not appreciably hydrolyze phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidic acid, and triglyceride. The present enzyme, named phosphatidylserine-phospholipase A1, is the first phospholipase that exclusively hydrolyses the sn-1 position and has a strict head group specificity for the substrate.
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DOI：
10.1016/s0021-9258(18)61070-1
发表时间：
1987-07
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
P. Matsudaira
通讯作者：
P. Matsudaira
DOI：
10.1073/pnas.84.6.1526
发表时间：
1987-03
影响因子：
11.1
作者：
M. Komaromy;M. Schotz
通讯作者：
M. Komaromy;M. Schotz
脂蛋白脂肪酶和肝脂肪酶：天冬酰胺连接的糖基化在功能酶表达中的作用。
影响因子：
6.5
作者：
Ben-Zeev,O;Stahnke,G;Liu,G;Davis,RC;Doolittle,MH
通讯作者：
Doolittle,MH
DOI：
10.1016/s0021-9258(17)32081-1
发表时间：
1994-08
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
K. S. Lee;J. Patton;M. Fido;L. K. Hines;S. Kohlwein;F. Paltauf;S. Henry;D. E. Levin
通讯作者：
K. S. Lee;J. Patton;M. Fido;L. K. Hines;S. Kohlwein;F. Paltauf;S. Henry;D. E. Levin
DOI：
--
发表时间：
1992
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Emmerich,J;Beg,OU;Peterson,J;Previato,L;Brunzell,JD;BrewerJr,HB;Santamarina-Fojo,S
通讯作者：
Santamarina-Fojo,S