Inhibition of a Protein Tyrosine Phosphatase Using Mesoporous Oxides

The feasibility of utilizing mesoporous matrices of alumina and silica for the inhibition of enzymatic activity is presented here. These studies were performed on a protein tyrosine phosphatase by the name chick retinal tyrosine phosphotase-2 (CRYP-2), a protein that is identical in sequence to the human glomerular epithelial protein-1 and involved in hepatic carcinoma. The inhibition of CRYP-2 is of tremendous therapeutic importance. Inhibition of catalytic activity was examined using the sustained delivery of p-nitrocatechol sulfate (pNCS) from bare and amine functionalized mesoporous silica (MCM-48) and mesoporous alumina (Al₂O₃). Among the various mesoporous matrices employed, amine functionalized MCM-48 exhibited the best release of pNCS and also inhibition of CRYP-2. The maximum speed of reaction v_max (=160 ± 10 μmol/mnt/mg) and inhibition constant K_i (=85.0 ± 5.0 μmol) estimated using a competitive inhibition model were found to be very similar to inhibition activities of protein tyrosine phosphatases using other methods.