تثبيط فعالية انزيم بولي امين اوكسيديز المنقى جزئيا من مصل الاشخاص المصابين بداء السكر غير المعتمد على الانسولين

Abstract

The research included the detection of polyamine oxidase [E.C.1.4.3.6] activity in serum of non-insulin-dependent diabetes patients (Type II). Optimal conditions for crude PAO activity were determined in serum using spermine as substrate. PAO activity was found to be proportional with time of reaction up to (60) sec. The maximum activity was obtained by using phosphate buffer at pH = 5, temperature (30) C, incubation time (5) min. and (100) l of enzyme volume.By using Linweaver-Burk plot, it was found that Vmax to be (0.44) enzyme unit/ml and Km value to be (2) mM with spermine as substrate. K+ was the most potent activator for PAO activity. It activated the enzyme by (200%). PAO was purified from serum by dialysis and anion exchange chromatography techniques. Two PAO isoenzymes I and II were obtained, with specific activity of (0.39) and (0.46) respectively, and with purification fold of (169.5) and (20) respectively compared to crude enzyme. Inhibition of partially purified PAO was studied by Vitamin E, Metformine drug and Metformine with Vitamin E. The higher inhibitory effects obtained at the lower concentrations of inhibitors 10-5, 10-4 and 10-5 M respectively.The inhibition type of PAO by using these concentrations was competitive. Km value without inhibitors was (1.33) mM, then became Km` (2.5, 5 and 6.6) mM with inhibitors respectively. However Vmax value remained (0.27) enzyme unit/ml. The inhibition properties shown, the inhibition constant Ki values were (0.53, 0.29 and 0.20) mM for each inhibitor respectively. Accordingly, these results indicate that inhibitory effect of Melformine with Vitamin E was a better than Metformine and this was a best of Vitamin E.Key words: