Abstract
Bacto-phytohemagglutinin P (PHA-P) possesses at least five biological activities including hemagglutinating activity (HA), leukoagglutinating activity (LA), precipitating activity (PA), mitogenic activity (MA) and cytotoxic activity (CA). Hitherto, it is discouraging that the interrelation of these activities appeared rather controversial in the literatures. In the present study commercially purchased PHA-P was fractionated through various ion exchange chromatographies and its modification with thermal denaturation (85°C and 95°C), reduction/alkylation and absorption with chicken erythrocytes was performed in an attempt to clarify the correlation of these activities and further qualify the MICC activity. From the studies it was appreciated that MICC activity of PHA was a unique character independent of the other factors in that it was thermostable even under 95°C boiling. Another fact revealed that LA may possess a minority of cytotoxic activity since complete avoidance of LA led to more or less diminish in CA. There were also certain evidences in our study to suggest that CA or MA merely reflected the discrete functional facets of the same moiety or subunit of PHA-P molecule. In other words, MICC was assayed in short duration during which the MA was insufficient to express. Once the incubation was long enough the same moiety would exhibit potent lymphocyte-stimulating activity in addition to the cytotoxic activity. The two activities fluctuated and correlated in parallel.
