Regulation of a candidate aminophospholipid-transporting ATPase by lipid.
Regulation of a candidate aminophospholipid-transporting ATPase by lipid.
复制标题
脂质对候选氨基磷脂转运 ATP 酶的调节。
DOI：
10.1021/bi00096a040
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发表时间：
1993
期刊：
影响因子：
2.9
通讯作者：
Daleke,DL
中科院分区：
文献类型：
--
作者：
Zimmerman,ML;Daleke,DL
摘要：在洗涤剂-脂质-蛋白质混合胶束中，研究了脂质环境对人红细胞钒酸敏感性Mg ~（2+）-ATP酶激活的影响。ATP酶活性最大限度地刺激磷脂酰丝氨酸。其他阴离子二酰基甘油磷脂（磷脂酸、心磷脂、磷脂酰甘油和磷脂酰肌醇）支持25-100%的磷脂酰丝氨酸刺激活性。另一种氨基磷脂，鸡蛋PE，支持38%的磷脂酰丝氨酸刺激活性。磷脂酰肌醇、4-磷酸磷脂酰肌醇、4，5-二磷酸磷脂酰肌醇也能刺激ATP酶活性，但活性随脂质磷酸化程度的增加而降低。单酰基负电荷脂质（溶血磷脂酰丝氨酸，脂肪酸）和两性离子脂质（磷脂酰胆碱和鞘磷脂）没有激活酶。ATP酶的活性依赖于磷脂脂肪酰基链的组成：ATP酶活性随PS酰基链长度的增加而增加，最佳脂肪酸组成为一种饱和脂肪酸和一种不饱和脂肪酸。然而，长的，不饱和的酰基链的要求可以满足非活化脂质。这种ATP酶的特性与Mg ~（2+）-ATP依赖的氨基磷脂翻转酶的特性相似，表明它可能与转运蛋白有关。跨膜磷脂不对称性是生物膜的一个基本特征。氨基磷脂，磷脂酰丝氨酸（PS）1和磷脂酰乙醇胺（PE），主要位于细胞膜的细胞质表面，而含胆碱的β-磷脂，鞘磷脂（SM）和磷脂酰胆碱（PC），优先位于质膜的外表面或内部细胞器的内腔表面。这种分布部分由PS和PE特异性转运蛋白或“翻转酶”维持，该转运蛋白将含胺磷脂转运至细胞表面单层[最近的综述见Devaux（1991）和Schroit和Zwaal（1991）]。氨基-磷脂转运需要Mg 2 +-ATP（Seigneuret & Devaux，1984; Daleke & Huestis，1985，1989）并且对巯基试剂敏感（Daleke & Huestis，1985;康纳& Schroit，1988; Truong埃塔尔，1993）、精氨酸试剂（Daleke，1990）、Ca 2+（Bitbol等，1987）和钒酸盐（Bitbol等人，1987年）。翻转酶的底物特异性是严格的，并且在甘油骨架或头基结构中几乎不发生变化。甘油立体化学的反转（Martin & Pagano，1987）或二酰基甘油主链的取代
Revised Manuscript Received July 29, 1993• abstract: The effect of lipidenvironment on the activation of a vanadate-sensitive Mg2+-ATPase purified from human erythrocytes was studied in detergent-lipid-protein mixed micelles. ATPase activity was stimulated maximally by phosphatidylserine. Other anionic diacylglycerophospholipids (phosphatidic acid, cardiolipin, phosphatidylglycerol, and phosphatidylinositol) supported 25-100% of the phosphatidylserine-stimulated activity. Another aminophospholipid, egg PE, supported 38% of the phosphatidylserine-stimulated activity. Thephosphoinositides (phosphatidylinositol, phosphatidylinositol 4-phosphate, phosphatidylinositol 4, 5-bisphosphate) also stimulated the ATPase; however, activity decreased with increasing lipid phospho-rylation. Monoacyl negatively charged lipids (lysophosphatidylserine, fatty acids) and zwitterionic lipids (phosphatidylcholine and sphingomyelin) did not activate theenzyme. ATPase activation was dependent on phospholipid fatty acyl chain composition: ATPase activity increased with increasing PS acyl chain length, and the optimal fatty acid composition was one saturated and one unsaturated fatty acid. However, the long, unsaturated acyl chain requirement could be satisfied by nonactivating lipids. The characteristics of this ATPase are similar to those of the Mg2+-ATP-dependent aminophospholipid flippase, suggesting that it may be associated with the transporter.Transmembrane phospholipid asymmetry is a characteristic and essential feature of biological membranes. The aminophospholipids, phosphatidylserine (PS) 1 and phosphatidylethanolamine (PE), are located primarily on the cytoplasmic face of cell membranes, while the choline-containing phos-pholipids, sphingomyelin (SM) and phosphatidylcholine (PC), are located preferentially on the external face of the plasma membrane or the lumenal face of internal organelles. This distribution is maintained in part by a PS-and PE-specific transporter, or “flippase”, which transports amine-containing phospholipids to the cytofacial monolayer [for recent reviews, see Devaux (1991) and Schroit and Zwaal (1991)]. Amino-phospholipid transport requires Mg2+-ATP (Seigneuret & Devaux, 1984; Daleke & Huestis, 1985, 1989) and is sensitive to sulfhydryl reagents (Daleke & Huestis, 1985; Connor & Schroit, 1988; Truong etal., 1993), arginine reagents (Daleke, 1990), Ca2+(Bitbol et al., 1987), and vanadate (Bitbol et al., 1987). The substratespecificity of the flippase is strict and tolerates few changes in glycerol backbone or headgroup structure. Inversion of glycerol stereochemistry (Martin & Pagano, 1987) or substitution of the diacylglycerol backbone