Hebert T E, Fackrell H B
Department of Biological Sciences, University of Windsor, Ontario, Canada.
Biochim Biophys Acta. 1987 Dec 18;916(3):419-27. doi: 10.1016/0167-4838(87)90188-9.
The effects of 1,2-cyclohexanedione and phenylglyoxal on staphylococcal alpha-toxin were studied. Modification of one arginine residue in alpha-toxin was sufficient to render the toxin nonhemolytic with no conformational change. Modified alpha-toxin did not protect cells from hemolysis by native alpha-toxin. An arginine residue is therefore at or near the binding site of alpha-toxin. Trypsin digestion of modified alpha-toxin generated a 20 kDa fragment which was isolated using a boric acid gel column. Upon regeneration, this 20 kDa fragment was not recognized by a population of antibodies which prevented alpha-toxin binding. The fragment was recognized by antibodies directed against post-binding events. However, the antibinding antibodies recognized the intact modified toxin. This leads us to conclude that antibinding determinants are not found directly in the binding site or are conformationally masked.
研究了1,2 - 环己二酮和苯乙二醛对葡萄球菌α - 毒素的影响。α - 毒素中一个精氨酸残基的修饰足以使毒素失去溶血活性，且构象无变化。修饰后的α - 毒素不能保护细胞免受天然α - 毒素的溶血作用。因此，一个精氨酸残基位于α - 毒素的结合位点或其附近。用胰蛋白酶消化修饰后的α - 毒素产生一个20 kDa的片段，该片段用硼酸凝胶柱分离。再生后，一群能阻止α - 毒素结合的抗体不能识别这个20 kDa的片段。针对结合后事件的抗体能识别该片段。然而，抗结合抗体能识别完整的修饰毒素。由此我们得出结论，抗结合决定簇并非直接存在于结合位点，或者在构象上被掩盖。
