Electron Microscopic Analysis of CAT Pore-orming Effect on Human Erythrocyte Membrane

βγ-CAT is a naturally existing multifunctional protein complex of non-lens βγ-crystallin and trefoil factor from Bombina maxima skin secretions. In this paper, we first analysed the time-response curve of hemolysis and intracellular potassium efflux induced by βγ-CAT on human erythrocytes. After βγ-CAT (3 nmol/L) in human erythrocytes was treated at 37℃ for 5 min, we found that about 93.31±5.89% (P<0.01) of the intracellular potassium ions leaked, whereas the percentage of hemolysis was only13.12±1.92 % (P<0.05). We employed electron microscopy to observe the erythrocytes’ morphological changes and found erythrocytes were swollen and some had globular structures occurring on the cell surfaces, and fast releasing hemoglobins. These results indicated that the hemolytic effect of βγ-CAT on human erythrocyte membranes was due to intracellular potassium ion’s rapid efflux. These results demonstrate morphological proof in understanding the mechanism of βγ-CAT pore-forming effect on human erythrocytes.

Keywords
Trefoil factor; Non-lens bg-crystallin; bg-CAT; Pore-forming protein; Scanning electron microscopy; Transmission electron microscopy