Huntley J S, Hall A C
University Laboratory of Physiology, Oxford, UK.
Biochim Biophys Acta. 1996 Jun 11;1281(2):220-6. doi: 10.1016/0005-2736(96)00020-x.
Vibrio parahaemolyticus is an important enteric pathogen that produces an exotoxin prepared as Kanagawa haemolysin (KH). Isotope flux techniques were used to analyse toxin action on the basal permeability of human erythrocytes. KH induced a cation leak that was (i) rapid in onset (lag phase < 1 min), (ii) 'pore-like' in terms of kinetic characteristics, and (iii) of high magnitude initially (first 10 min) and then subsequently lower (but still raised with reference to control cells). The susceptibilities of the induced flux pathway to washout in initial and later periods suggested a protracted binding time course for toxin action. Neuraminidase treatment of erythrocytes enhanced both haemolysis and flux induced by KH, suggesting that the affinity of the toxin for the membrane had increased, possibly as a result of additional toxin receptors being unmasked by this enzyme. These results show that KH elevates the basal permeability of human erythrocytes in a complex manner, a process that probably underlies the deleterious effects of this toxin on cellular function.
副溶血性弧菌是一种重要的肠道病原体，它能产生一种被制备为神奈川溶血素（KH）的外毒素。采用同位素通量技术分析该毒素对人红细胞基础通透性的作用。KH诱导了阳离子泄漏，其特点为：（i）起始迅速（滞后阶段<1分钟），（ii）动力学特征呈“孔样”，（iii）最初幅度较高（前10分钟），随后降低（但相较于对照细胞仍升高）。诱导通量途径在初期和后期对洗脱的敏感性表明毒素作用的结合时间过程较长。用神经氨酸酶处理红细胞可增强KH诱导的溶血和通量，这表明毒素对膜的亲和力增加，可能是由于该酶使额外的毒素受体暴露所致。这些结果表明，KH以复杂的方式提高人红细胞的基础通透性，这一过程可能是该毒素对细胞功能产生有害影响的基础。
