Lectin Secreted From Frog (Hylarana Guentheri) In Chongqing:Purification,Characterization And Bioactive Properies

Living environments of amphibians are complex and diverse, and they have been able to adapt to such habtat entirely due to the long-term biological evolution caused by their shape and physiological change. Because the skins of amphibians are generally bare, wet, the harsh environments where they live provides a natural breeding for bacteria and germs. In order to defense against these foreign intruders (bacteria), the skins of amphibians secreted mucus, which contained a variety of special active substances with special structures and functions. Recent studies found that these active substances played a lot of roles throughout the lifetime of amphibians.In order to study characterization, biological activity and physical-chemical properties of the skin extracts secreted from Bufo gargarizans,Rana nigromaculatta Hallowel,Hylarana guentheri collected in Chongqing, we used the four methods (Ethyl ether stimulation method, electrical stimulation method, the adrenaline shots, and skinning method) to collect the secretions for our research and the results as follows:1,Respectively using different methods to collected the secretions of three different frogs, we found that the secretions of only one of three frogs(Hylarana guentheri) had antibacterial activity, blood-clotting activity and analgesic effect.2,After the separation and purification of HPCL, except the skinning method, the ethyl ether stimulation, the electrical stimulation and the adrenaline shots have little differences. By the related activity assay, the bioactive peaks among all fractions were confirmed, and we found that the ether extract group has higher biological activity than others. So we purified its activity peaks once again.3,We got a single peak A after re-purification and examed its physical and chemical properties.The following study found that the component can agglutinate red blood cells of rabbit and human only.The agglutination titter is1.13ug/ml.The agglutination activity can be inhibitied by mannan, this component's nature is stable and it have biological activities during a wide range of temperature and pH range. It is rather stable when the temperature is from0℃to60℃and still has activity after heating20min at100℃. It is stable in pH4-9and most suitable pH is8. Metal ions have almost no effect on its activity, but guanidine hydrochloride and SDS have strong impact on its activity, whereas urea has weak effect on its activity.