MODULATION OF INTERACTION OF WGA WITH MEMBRANE RECEPTOR SITES BY A MEMBRANE MOBILITY AGENT AND BY TRYPSIN

Abstract

Publisher Summary This chapter provides an overview of the modulation of interaction of wheat germ agglutinin (WGA) with membrane receptor sites. In an experiment described in the chapter, membrane mobility agents, 2-(2 methoxy)-ethoxyethyl 8-(2-n-octylcyclopropyl)-octanoate (A 2 C), and trypsin were used to alter the distribution of membrane sites of WGA on interphase murine mastocytoma cells and to examine the behavior of the cells resulting from this alternation. Three criteria using fluorescein labeled WGA (FITC–WGA) were used: (1) cell agglutination, (2) cytolysis, and (3) “capping.” The addition of WGA causes extensive agglutination of the cells within a few minutes without any cytolytic effect. FITC–WGA bound to the cells is distributed in small clusters all around the cell membrane. Treatment of the cells with A 2 C or trypsin prior to the addition of WGA promotes a redistribution of WGA membrane sites complexes to a “cap”-like arrangement. “Cap” formation and cytolysis were inhibited by pretreatment of the cells. Addition of A2C to the unlysed cells remaining after pretreatment with trypsin and incubation with WGA does not lead to further cytolysis by reincubation with WGA and suggests that the same population of cells that respond to A2C also respond to trypsin.