STUDY OF THE HEMOLYTIC PROCESS AND RECEPTORS OF THERMOSTABLE DIRECT HEMOLYSIN FROM VIBRIO-PARAHAEMOLYTICUS

The haemolytic action of I-125-labelled thermostable direct haemolysin from Vibrio arahaemolyticus was studied on human and equine erythrocy tes. In the first step, the haemolysin bound to the membranes of both erythrocyte species. This binding seemed temperature-independent. Then , for human erythrocytes, haemolysin produced cell disruption, and hae moglobin was released. Following this step, haemolysin was also releas ed in a temperature-dependent manner. In contrast, equine erythrocytes were not disrupted, and no release of haemolysin occurred. The recept ors of labelled haemolysin were analysed by assaying the lipid/toxin i nteraction on a nylon membrane and by binding on thin-layer chromatogr ams. The ganglioside asialo-G(M2) was found to be the most potent rece ptor, but asialo-G(M1) and lactocerebroside may also have been involve d.