WERNER G. JAFFÉ, OLLIE BRUCHER and AURA PALOZZO
Laboratorio de Bioquímica, Facultad de Ciencias Universidad Central de Venezuela (Caracas)
When the hemagglutinating action of extracts from ground seeds of different lines or cultivars of beans (Phaseolus vulgaris) was tested with blood cells from different animals, four different patterns of activity were distinguished. The most common type, called A, agglutinated all blood types tested with the exception of cow blood cells which were rendered susceptible to agglutination by treatment with trypsin. Type-B beans were active on all the blood types except trypsin-treated cow blood, type-C bean extracts agglutinated strongly only trypsin-treated cow blood cells and pronase-treated rat and hamster cells. The last type, called D, had little if any activity with the exception of its action on pronase-treated hamster blood cells.
The hemagglutinating activity on trypsin-treated cow blood cells of A- or C. type extracts was not destroyed after 90 minutes heating at 80° C but the activity on rabbit blood cells was lost.
The hemagglutinating activity of extracts of any one of these four bean types could be absorbed on rabbit or trypsin-treated cow blood cells and released again by heating to 56° C although some of the extracts would not agglutinate these types of blood cells. The disappearance of at least one component of the bean extracts after repeated absorption with blood cells was detected by immunoelectrophoresis. This component was detected in the supernatant after release from the cells. The corresponding immunoprecipitation line could be stained with sudan black indicating that it was caused by a lipoprotein.
The possibility that the A-type activity is caused by a combination of B- and C-type hemagglutinins is discussed. The results of a cross-breeding experiment which revealed the fact that this activity is inherited as a single, dominant trait is evidence against this possibility.
The use of trypsin-treated cow blood cells and rabbit rbc for testing different fractions from bean extracts in recommended.
The existence of phytohemagglutinins (PHA) in the seeds of kidney beans (Phaseolus vulgaris) has been known since LANDSTEINER and RAUBITSCHEK’S first observation in 1908 (9). These authors not only discovered hemagglutinating activity in the extracts of seeds from different legumes but pointed out also that many of these extracts act only on the red cells from some animal species and not on those from others. Kidney bean extracts, however, were active with all the blood samples. Indeed, when red blood cells fram 32 different animal species were tested with bean extracts in our laboratory, agglutination activity was observed in all cases except with cow blood cells which had to be treated with trypsin to make them sensitive to the agglutinating action (7). In some samples the hemagglutinating principIe could not be found because the extracts of the seeds of some strains of kidney beans (Phaseolus vulgaris) and ofwild beans (Phaseolus aborigineus) did not agglutinate the erythrocytes tested (3)