Toxic effects of Kintoki bean (Phaseolus vulgaris) lectin on cultured animal cells.

Abstract

Effects of a toxic lectin from Kintoki beans (Phaseolus vulgaris, cultivar, Kintoki) on four types of animal cells were investigated. The cells used in this study were mouse L 929, human HeLa S3, and tendon and liver cells from chick embryo. The Kintoki bean lectin agglutinated these cells not only in suspension but also in monolayer, resulting in the marked growth inhibition of these cells. The incorporations of 3H-thymidine and 3H-leucine into trichloroacetic acid insoluble fraction of the cells were considerably inhibited by this lectin. There was, however, some lag period before the revelation of the inhibition. Kintoki bean lectin bound to these cells within 1 hr. The type of the lectin receptor seemed uniform for each cell type and the number of the binding sites per cell was different from cell type to cell type. When Kintoki bean lectin was removed from the culture medium, these cells slowly recovered back to normal growth.