Separation and Study of some Kinetic Properties of Senescence Marker Protein -30 in Human Plasma

The research includes the isolation of senescence marker protein-30 (SMP-30) from human plasma of normal young male age 25 year, the factors affecting the activity of the enzyme and determination of its molecular weight. One band had been isolated by gel filtration chromatography from the proteinous supernatant produced by precipitation by ammonium sulfate (60%) after dialysis and separation by cooling centrifuge. Apparent molecular weight of the isolated enzyme using gel filtration chromatography was (34672) Dalton. The results also showed that the optimum conditions of SMP-30 activity were obtained at (100 μg/ml) of enzyme concentration and phosphate buffer (0.022 mol/l) as a buffer at pH (8) for (18) minutes at (49°C) using (14 mmol/l) of gluconolactone (GL) as a substrate,. Using Line Weaver–Burk plot, the values of maximum velocity (Vmax) and Michaelis constant (Km) were (0.65 μmol/ min) and (5.6 mmol/l) respectively. Beside of, the study showed the inhibition effect of some chemicals and drugs on the enzyme activity, Phenylphrine, neomycin and mercuric chloride possessed a noncompetitive inhibition and anhydrous caffein possessed a competitive inhibition and arsenate meta sodium possessed a uncompetitive.