Trust T J, Doig P, Emödy L, Kienle Z, Wadström T, O'Toole P
Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada.
Infect Immun. 1991 Dec;59(12):4398-404. doi: 10.1128/iai.59.12.4398-4404.1991.
The ability of 16 isolates of the human gastroduodenal pathogen Helicobacter pylori to bind 125I-radiolabelled tissue proteins was quantitated by liquid-phase assay. While capable of binding generally low levels of collagen types I and II, vitronectin, and fibronectin (average binding, 8%; highest binding, 23%), the various H. pylori isolates were good binders of the basement membrane proteins collagen type IV and laminin (average binding, 27%; highest binding, 60%). Campylobacter species tested bound lower levels of collagen type IV and laminin (average binding, 12%; highest binding, 17%). Trypsin and proteinase K treatment of H. pylori cells markedly reduced the binding of collagen type IV and laminin, as did heat treatment, suggesting that the binding of basement membrane proteins is mediated by bacterial surface proteins. Binding of both basement membrane proteins was rapid and saturable. 125I-collagen type IV binding to H. pylori 915 was inhibited by preincubation with unlabelled collagen type IV but was not inhibited by laminin or a number of other proteins. Once bound, radiolabelled collagen type IV but was not displaced by an excess of unlabelled collagen type IV, indicating that the binding interaction was of high affinity. Binding of laminin was partially reversible, and analysis in a solid-phase nonradiolabel assay showed that the interaction was of high affinity, with a Kd of 7.9 nM. This interaction was affected by salt, indicating the presence of a hydrophobic component in the ability of H. pylori to bind laminin.
采用液相分析法对16株人胃十二指肠病原体幽门螺杆菌结合¹²⁵I放射性标记组织蛋白的能力进行了定量分析。虽然这些幽门螺杆菌分离株一般能结合低水平的I型和II型胶原蛋白、玻连蛋白和纤连蛋白（平均结合率为8%；最高结合率为23%），但它们都是基底膜蛋白IV型胶原蛋白和层粘连蛋白的良好结合剂（平均结合率为27%；最高结合率为60%）。所检测的弯曲杆菌属菌株结合IV型胶原蛋白和层粘连蛋白的水平较低（平均结合率为12%；最高结合率为17%）。用胰蛋白酶和蛋白酶K处理幽门螺杆菌细胞，以及热处理，均显著降低了IV型胶原蛋白和层粘连蛋白的结合，这表明基底膜蛋白的结合是由细菌表面蛋白介导的。两种基底膜蛋白的结合都很快且具有饱和性。¹²⁵I-IV型胶原蛋白与幽门螺杆菌915的结合可被未标记的IV型胶原蛋白预孵育所抑制，但不受层粘连蛋白或其他多种蛋白的抑制。一旦结合，放射性标记的IV型胶原蛋白不会被过量的未标记IV型胶原蛋白取代，这表明结合相互作用具有高亲和力。层粘连蛋白的结合部分是可逆的，固相非放射性分析表明这种相互作用具有高亲和力，解离常数为7.9 nM。这种相互作用受盐的影响，表明幽门螺杆菌结合层粘连蛋白的能力中存在疏水成分。
