Nolte F S, Kapral F A
Infect Immun. 1981 Mar;31(3):1086-93. doi: 10.1128/iai.31.3.1086-1093.1981.
The addition f [3H]isoleucine to a chemically defined medium resulted in the production of delta-toxin (DT) with a high specific radioactivity (0.47 microCi/mg). The purified tritium-labeled toxin ([3H]DT) was found to migrate in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a single band with a molecular weight of 1,600. Upon electrofocusing, [3H]DT yielded one major peak (pI = 5.90) and two minor peaks (pI = 5.10, 6.95) of radioactivity. The percentage of [3H]DT associated with pelleted fractions of intact erythrocytes or erythrocyte ghosts remained fairly constant over a 100-fold range of toxin concentrations. Erythrocyte ghosts, however, bound more [3H]DT than did intact erythrocytes when exposed to the same concentration of toxin. Erythrocytes maintained in isotonic sucrose were more susceptible to toxin than erythrocytes suspended in saline, but did not bind more [3H]DT. The binding of [3H]DT to erythrocyte ghosts was found to be temperature dependent from 0 to 20 degrees C but was constant from 20 to 50 degrees C.
在化学限定培养基中添加[3H]异亮氨酸可产生具有高比放射性（0.47微居里/毫克）的δ-毒素（DT）。纯化的氚标记毒素（[3H]DT）在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳中迁移时呈现为一条分子量为1600的单带。经等电聚焦后，[3H]DT产生一个主要放射性峰（pI = 5.90）和两个次要放射性峰（pI = 5.10、6.95）。在毒素浓度相差100倍的范围内，与完整红细胞或红细胞血影沉淀部分结合的[3H]DT百分比保持相当恒定。然而，当暴露于相同浓度的毒素时，红细胞血影比完整红细胞结合更多的[3H]DT。维持在等渗蔗糖中的红细胞比悬浮在盐水中的红细胞对毒素更敏感，但结合的[3H]DT并不更多。发现[3H]DT与红细胞血影的结合在0至20摄氏度之间依赖温度，但在20至50摄氏度之间保持恒定。
