Kinetics of yeast dissociation from lectin beads: III. potassium chloride

Abstract

Here we quantitatively examine the kinetics of salt‐induced dissociation of mannose‐rich yeast (Saccharomyces cerevisiae) from concanavalin A (Con A) derivatized agarose beads. This model can be used to test a reagent's ability to elute glycan‐containing molecules from lectin beads in purification protocols and to remove pathogens from human cell surfaces in drug development studies. We chose one salt concentration (4.0 M potassium chloride) in this study in order to do many replicate experiments to statistically evaluate the reliability of this model system. Future work will test many reagent concentrations in dose‐response experiments to determine reagents that are most effective at the lowest concentrations. In 65 repeated trials, the kinetics of dissociation of yeast previously bound to Con A derivatized agarose beads in the presence and absence of the salt over a 60 min time course was measured. This was done by simply counting the yeast remaining on the beads at each time point. A repeated measures‐ANOVA indicated a significant effect of the salt on the number of bound yeast (F=70, p less than 0.0001) as well as a significant interaction between the treatment and time elapsed (F=25, p less than 0.0001). Two‐sample t‐tests comparing salt treated samples with controls indicated substantially increased dissociation in the salt treated samples (20 min p less than 0.0001, 40 min p less than 0.0001, 60 min p less than 0.0001). What is new here is the model. We know of no past work that measures dissociation kinetics in so simple, inexpensive and easily visualized a manner (Supported by NIH NIGMS SCORE S0648680, MARC, RISE, the Joseph Drown Foundation and the Sidney Stern Memorial Trust).