水稻白葉枯病病原細菌的線狀噬菌體 X f 之血清學研究

Abstract

中文摘要 抗血清與 X f 之作用為一種快速反應，37℃ , 10 分鐘幾乎可達完全破壞，而兩者之接台為非可逆反應.為探求抗血清與 X f 作用之機制，將抗血清與 X f混合後，以不同等級濃度蔗糖離心法分析，知道 X f 的大小發生變化，以同位素雙重標誌之 X f 與抗血清作用後，利用不同等級密度氣化銫離心法分析抗血清作用後 X f 的構造，發現有部份 DNA 會暴露出來，故知抗血清可將 X f 蛋白質部份溶化。在電子顯微鏡下觀察，發現 X f 的外圍有抗體附著，而對照組則無此現象. X f 之抗血清利用瓊脂雙重擴故法及免疫電泳法分析，發現 X f 與其抗血清形成兩條沉澱帶，其中之一靠近抗血清井較小而模糊，另一條靠近抗原井較大而清楚，知 X f 抗血清具有兩種不同的抗體。此兩抗體與X f 的DNA無關，但與 X f 的蛋白質外殼有密切的關係。當 X f 的蛋白外殼經 SDS 處理後曾溶解，溶解物在水中透析，則蛋白外殼的兩種蛋白質subunit分開， B 蛋白沉澱出而A 蛋白溶於水中，透析後經離心可將 A 蛋白與 B 蛋白分開。分開的 A 蛋白與 B 蛋白分別與抗血情作用，可證明X f 所具有的二種抗原，一種為蛋白質 B ，另外一種可能為蛋白質 A 。

Abstract When X f was reacted with it’s specific antiserum, the reaction was very fast, 100% of phage was inactivated within 10 minutes at 37°C. The mechanism of X f—antiserum interaction was studied by the analysis of the structure of X f—antiserum complexes. Based on the analysis in sucrose gradient centrifugation, the size of X f that reacted with antiserum was smaller than that of X f itself. Again, based on CsCl jensity gradient centrifugation analysis, the density of X f that reacted with antiserum became denser than that of Xf itself. Evidently, the part of coat protein was broken and DNA was released out. This phenomenon was also partly confirmed by the observation of electron microscopy. The agar gel diffusion and immunoelectrophoresis analysis showed that two antibodies were induced by X f. Since X f protein coat contains two types of protein subunits, the relationship between two protein subunits and their responded antibodies was studied. It was found that two antibodies were respectively induced by protein A and protein B, and purified X f DNA does not react with antibodies.