منابع مشابه
Purine Nucleoside Phosphorylase ( PNP ) and Adenosine Deaminase ( ADA ) Activities
New techniques have been devised for the cytochemical demonstration of purine nucleoside phosphorylase (PNP) and adenosine deaminase (ADA) activities in unfixed human lymphocytes. A suspension of living lymphocytes is mixed with agarose sol containing the reagents for the detection of PNP or ADA activity on a glass slide. The mixture solidifies. is incubated, and then dried for lightmicroscopic...
متن کاملPurine Nucleoside Phosphorylase
Purine nucleoside phosphorylase (EC 2.4.2.1) from bovine spleen is a trimeric enzyme that readily dissociates to the monomer. Dilution of enzyme from 20 to 0.02 pg of protein/ml is accompanied by a greater than 50-fold increase in the specific activity (utrimer = 0.23 nmol/min/pg; umonomer = 12.5 nmol/min/pg). Gel permeation chromatography in the presence of the substrate phosphate shows the en...
متن کاملRabbit Erythrocyte Purine Nucleoside Phosphorylase
1. Concave-downward double-reciprocal plots were obtained for rabbit erythrocyte purine nucleoside phosphorylase when the concentration of Pi was varied over a wide range at a fixed saturating concentration of either inosine or deoxyinosine. Similar behaviour was also displayed by the calf spleen enzyme. 2. The degree of curvature of double-reciprocal plots was greatly modified by the presence ...
متن کاملProperties of purine nucleoside phosphorylase (PNP) of mammalian and bacterial origin.
Purine nucleoside phosphorylase (PNP), from calf spleen, human erythrocytes and E. coli have been examined with regard to structural requirements of substrates and inhibitors. Kinetic parameters (Km, Vmax/Km) for a variety of N(1) and/or N(7)-methylated analogues of guanosine, inosine and adenosine have been evaluated for all three enzymes. The substrate and/or inhibitor properties of purine ri...
متن کاملPurine Nucleoside Phosphorylase of Rabbit Liver
Initial velocity studies and product inhibition patterns for purine nucleoside phosphorylase from rabbit liver were examined in order to determine the predominant catalytic mechanism for the synthetic (forward) and phosphorolytic (reverse) reactions of the enzyme. Initial velocity studies in the absence of products gave intersecting or converging linear double reciprocal plots of the kinetic da...
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ژورنال
عنوان ژورنال: Atlas of Genetics and Cytogenetics in Oncology and Haematology
سال: 2018
ISSN: 1768-3262
DOI: 10.4267/2042/68966