[Mechanisms of protease-induced cell aggregation. II. The effect of trypsin on the structural state of the plasma membrane of chick embryo fibroblasts].

Using freeze-etching, registration of kinetics of tryptophane phosphorescence quenching at room temperature, and measuring the cell electrophoretic mobility, a study has been made of the influence of a short-term treatment (5-10 min) with a low concentration of trypsin (2-100 microgram/ml) on the chick embryo fibroblasts removed from the monolayer with EDTA and suspended in the Henks solution. It is shown that trypsin induces a structural rearrangement of the plasma membrane which is manifested in clustering intramembrane globular particles. Trypsin-induced rearrangement of the plasma membrane is accompanied by an increase in the negative charge of the cell surface. The results obtained by the phosphorescence method show that structural rearrangements involve alongside with plasma membranes the majority of intracellular proteins.