Liang O D, Maccarana M, Flock J I, Paulsson M, Preissner K T, Wadström T
Department of Medical Microbiology, University of Lund, Sweden.
Biochim Biophys Acta. 1993 Nov 25;1225(1):57-63. doi: 10.1016/0925-4439(93)90122-h.
Multiple interactions between human vitronectin and Staphylococcus aureus strain V8 were observed. An upward-curved Scatchard plot indicated both high-affinity binding (Kd1 = 7.4 x 10(-10) M) with 260 binding sites per bacterial cell and moderate-affinity binding (Kd2 = 7.4 x 10(-8) M) with 5240 copies per cell. Negative cooperativity of this binding was characterized by its Hill coefficient of less than unity (0.70 +/- 0.08). Up to 60% of the vitronectin-bacteria interaction was unaffected by high ionic strength (i.e., 2.4 M NaCl), and was not inhibited by highly-charged heparin oligosaccharides. Various oligosaccharides (4-20 monosaccharide units) generated by partial deaminative cleavage of heparin were found to affect vitronectin binding to S. aureus. Short-chain-length oligosaccharides increase and long oligosaccharides inhibit vitronectin binding, in accordance with direct association of these saccharides with multimeric vitronectin. A protein having a molecular mass of 60 kDa was identified as a putative high-affinity staphylococcal vitronectin-binding protein. These results indicate that interaction of multimeric vitronectin, mostly present at extracellular matrix sites with multiple recognition sites on the S. aureus surface, may contribute to bacterial colonisation.
观察到人类玻连蛋白与金黄色葡萄球菌V8菌株之间存在多种相互作用。向上弯曲的Scatchard图表明，存在两种结合方式，一种是高亲和力结合（Kd1 = 7.4 x 10(-10) M），每个细菌细胞有260个结合位点；另一种是中等亲和力结合（Kd2 = 7.4 x 10(-8) M），每个细胞有5240个拷贝。这种结合的负协同性表现为其希尔系数小于1（0.70 +/- 0.08）。高达60%的玻连蛋白-细菌相互作用不受高离子强度（即2.4 M NaCl）的影响，也不受高电荷肝素寡糖的抑制。发现通过肝素部分脱氨基裂解产生的各种寡糖（4 - 20个单糖单位）会影响玻连蛋白与金黄色葡萄球菌的结合。短链寡糖增加而长链寡糖抑制玻连蛋白的结合，这与这些糖类与多聚体玻连蛋白的直接关联一致。一种分子量为60 kDa的蛋白质被鉴定为假定的高亲和力葡萄球菌玻连蛋白结合蛋白。这些结果表明，主要存在于细胞外基质部位的多聚体玻连蛋白与金黄色葡萄球菌表面多个识别位点之间的相互作用可能有助于细菌定植。
