Protein patterns of the nuclear matrix in differently proliferating and malignant cells

Summary The effect of cortisol on rabbit erythrocyte and reticulocyte acid phosphatase was studied. Isoenzymic form I (slow) was activated by cortisol, and protected towards inhibition by phosphate and fluoride. Incubation of isoenzyme III (fast) preparation with cortisol resulted in decrease of the enzyme activity and its affinity for substrate. The inhibition of form III by phosphate and fluoride was accelerated in the presence of cortisol. Form II, if present, was unaffected by cortisol. Reticulocyte isoenzymes I and III were less affected by cortisol than the erythrocyte enzymes.Abbreviations RBC red blood cells - AcP acid phosphatase - p-NPP p-nitrophenyl phosphate