Study of the haemolytic process and receptors of thermostable direct haemolysin from Vibrio parahaemolyticus

The haemolytic action of I-125-labelled thermostable direct haemolysin from Vibrio arahaemolyticus was studied on human and equine erythrocytes. 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 haemoglobin was released. Following this step, haemolysin was also released in a temperature-dependent manner. In contrast, equine erythrocytes were not disrupted, and no release of haemolysin occurred. The receptors of labelled haemolysin were analysed by assaying the lipid/toxin interaction on a nylon membrane and by binding on thin-layer chromatograms. The ganglioside asialo-G(M2) was found to be the most potent receptor, but asialo-G(M1) and lactocerebroside may also have been involved.