A serum lectin (mannan-binding protein) has complement-dependent bactericidal activity.
A serum lectin (mannan-binding protein) has complement-dependent bactericidal activity.
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血清凝集素（甘露聚糖结合蛋白）具有补体依赖性杀菌活性。
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
I. Yamashina
中科院分区：
文献类型：
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作者：
N. Kawasaki;Toshisuke Kawasaki;I. Yamashina
血清甘露聚糖结合蛋白（MBP）是甘露糖和N-乙酰葡糖胺的特异性凝集素，已知可通过经典途径激活补体，在大肠杆菌粗糙菌株K-12和B上进行的试验表明，MBP具有补体依赖性杀菌活性。用纯化的人血清MBP在Ca ~（2+）存在下致敏，然后与豚鼠补体孵育的细菌，与未用凝集素致敏的细菌相比，菌落形成能力显着降低。其杀菌作用与凝集素和补体的浓度有关。该反应的C4依赖性表明MBP的补体依赖性杀菌作用是通过经典途径表达的。细菌被凝集素聚集。125 I标记的MBP与细菌结合的Scatchard图分析表明，解离常数（Kd）和最大结合容量分别为6 × 10（-9）M和30，000个MBP分子/细胞。甘露糖、N-乙酰葡糖胺、N-乙酰甘露糖胺、L-岩藻糖、甘露庚酮糖和景天庚酮糖均能抑制MBP的结合，表明MBP识别构成E. coliK-12细胞壁; L-甘油-D-甘露庚糖对E.大肠杆菌B。这些结果表明，血清凝集素在宿主防御中具有重要的生理意义，与E.大肠杆菌粗糙菌株。
Serum mannan-binding protein (MBP), which is a lectin specific for mannose and N-acetylglucosamine and is known to activate complement via the classical pathway, has been revealed to have a complement-dependent bactericidal activity, as tested on rough strains of Escherichia coli, K-12 and B. The bacteria, which had been sensitized with purified human serum MBP in the presence of Ca2+, followed by incubation with guinea pig complement, showed a marked decrease of colony forming ability compared with those not sensitized with the lectin. The bactericidal effect depended on the concentrations of the lectin and complement. The C4-dependency of the reaction indicated that the complement-dependent bactericidal action by MBP is expressed through the classical pathway. The bacteria were aggregated by the lectin. Scatchard plot analysis of 125I-labeled MBP binding to the bacteria showed that the dissociation constant (Kd) and the maximum binding capacity were 6 x 10(-9) M and 30,000 molecules of MBP per cell, respectively. The binding was inhibited by mannose, N-acetylglucosamine, N-acetylmannosamine, L-fucose, manno-heptulose, and sedoheptulose, suggesting that MBP recognized L-glycero-D-manno-heptose and N-acetylglucosamine constituting the core oligosaccharide of the E. coli K-12 cell wall, and L-glycero-D-manno-heptose for E. coli B. These findings suggest the physiological significance of the serum lectin in host defense, being consistent with the avirulence of E. coli rough strains in mammals.