HIGH-AFFINITY BINDING OF THE BACTERICIDAL PERMEABILITY-INCREASING PROTEIN AND A RECOMBINANT AMINO-TERMINAL FRAGMENT TO THE LIPID-A REGION OF LIPOPOLYSACCHARIDE
HIGH-AFFINITY BINDING OF THE BACTERICIDAL PERMEABILITY-INCREASING PROTEIN AND A RECOMBINANT AMINO-TERMINAL FRAGMENT TO THE LIPID-A REGION OF LIPOPOLYSACCHARIDE
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DOI：
10.1128/iai.60.11.4754-4761.1992
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发表时间：
1992-11-01
影响因子：
3.1
通讯作者：
CONLON, PJ
中科院分区：
文献类型：
--
作者：
GAZZANOSANTORO, H;PARENT, JB;CONLON, PJ
杀菌/通透性增加蛋白(BPI)是中性粒细胞(PMN)研究的一种55 kDa的阳离子蛋白(NBPI55)。BPI对多种革兰氏阴性菌具有很强的杀菌活性，并能中和内毒素活性。NBPI55的N端片段显示了完整蛋白的杀菌和抗内毒素特性。为了进一步鉴定N-末端片段的生物学活性，制备并纯化了人BPI前199个氨基酸对应的重组蛋白(RBPI23)。RBPI23对大肠杆菌J5的抗菌活性与nBPI55相当。此外，rBPI23和nBPI55都能与广泛的R-型和S-型脂多糖以及天然和合成脂质A结合。mBPI55或rBPI23以同样的方式抑制放射性标记的nBPI55与脂多糖的结合。RBPI23和nBPI55的结合是特异的、可饱和的和高亲和力的，所有被测试的配体的表观K(D)约为2~5 nM。这些结果表明，BPI通过BPI分子氨基末端部分的残基识别细菌内毒素高度保守的脂蛋白A区域。
Bactericidal/permeability-increasing protein (BPI) is a 55-kDa cationic protein (nBPI55) elaborated by Polymorphonuclear neutrophils (PMN). BPI has potent bactericidal activity against a wide variety of gram-negative organisms and neutralizes endotoxin activities. An N-terminal fragment of nBPI55 exhibits the bactericidal and antiendotoxin properties of the holoprotein. To further characterize the biological activities of the N-terminal fragment, a recombinant protein (rBPI23) Corresponding to the first 199 amino acids of human BPI was produced and purified. rBPI23 had antibacterial activity equivalent to that of nBPI55, against Escherichia coli J5. Furthermore, both rBPI23 and nBPI55 bound identically to a broad range of R- and S-form lipopolysaccharides (LPS) and to natural and synthetic lipid A. Binding of radiolabeled nBPI55 to LPS was inhibited in an identical fashion by either mBPI55 or rBPI23. The binding of both proteins to immobilized E. coli J5 lipid A was inhibited in a comparable fashion by long- or short-chain LPS or lipid A. The binding of both rBPI23 and nBPI55 was specific, saturable, and of high affinity, with an apparent K(d) of approximately 2 to 5 nM for all ligands tested. These results demonstrate that BPI recognizes the highly conserved lipid A region of bacterial LPS via residues contained within the amino-terminal portion of the BPI molecule.