Interaction of lectins with surface membrane receptors of animal cells. I. Factors responsible for agglutinability of human, rabbit, and sheep erythrocytes with concanavalin A.

: A study of various factors influencing the Con A-mediated cell agglutinability failed to reveal any correlation between the agglutinability and the binding capacity of Con A-agglutinable and non-agglutinable human, rabbit, and sheep erythrocytes. Treatment with trypsin and neuraminidase on the one hand and chondroitin sulphate, polyvinylpyrrolidone and polylysine on the other hand made the agglutination of human erythrocytes possible, promoted the agglutination of rabbit erythrocytes, but had almost no effect on sheep erythrocytes, which agglutinated only after treatment with pronase or polylysine. The negligible effects of low temperature, NaN3, cytochalasine B and theophylline on cell agglutinability indicate that neither membrane fluidity, metabolic energy, cAMP, nor the microfilamentous apparatus are likely to play any important role in the Con A-mediated agglutination of erythrocytes. Differences in agglutinability between erythrocytes obtained from different animal species and subjected to different treatments with enzymes and polymers are explained as being due to alterations in the surface charge and the zeta potential.