Electrostatic Cell-to-Cell Adhesion by a Non-Proteolytic Component in a Protease Preparation

Abstract

A crude protease preparation from papaya (Protease Type III, Sigma) brought about reversible adhesion between adjacent cells of a variety of species including those of lymphoid, epithelial and fibroblastic origin at low ionic strength (below 100 mM). Sensitivities of the adhesion activity to ambient ionic strength, Ca²⁺, Mg²⁺ and pH indicated that the cell-cell contact is based on the electrostatic interaction. By ion-exchanger chromatography and gel-filtration chromatography it is suggested that the adhesion molecules in the protease preparation are dimers of cationic protein of 28 kDa distinct from the proteolytic component.