Glucose-6-phosphate dehydrogenase from human erythrocytes.

نویسندگان

  • P Cohen
  • M A Rosemeyer
چکیده

Human erythrocyte glucose 6-phosphate dehydrogenase (o-glucose 6-phosphate :nicotinamide adenine dinucleotide phosphate oxidoreductase, EC 1.1.1.49) was purified by column chromatography with diethylaminoethyl cellulose, calcium phosphate gel, carboxymethyl cellulose, diethylaminoethyl Sephadex, and carboxymethyl Sephadex. A homogeneous preparation was obtained in over-all yield of about 50%. The specific activity (750) and the yield were significantly greater than those so far reported for the enzyme. The sedimentation patterns of analytical ultracentrifugation and interference pattern of sedimentation equilibrium indicated a homogeneous preparation. The sedimentation constant (s%J was 10.0 S at a protein concentration of 0.3 %. The molecular weight was estimated as 240,000. The molecular weight was about 43,000 in 4 N guanidineHCl, indicating that the enzyme consisted of six similar size subunits. Removal of nicotinamide adenine dinucleotide phosphate from the enzyme caused dissociation into inactive (or weakly active) subunits with a molecular weight of about one-half of the native protein. The enzyme was partially inactivated by dilution without dissociating into subnuits. Optimal pH and Michaelis constants for the primary substrates were determined. Analogues of n-glucose 6-phosphate accepted as substrates were 2-deoxy-D-glucose 6-phosphate and D-galactose 6-phosphate. Nicotinamide adenine dinucleotide was a weak substrate. Amino acid composition of the enzyme was determined.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Protective Effect of Quercetin on Oxidative Stress in Glucose-6-Phosphate Dehydrogenase-Deficient Erythrocytes in Vitro

Glucose-6-phosphate dehydrogenase (G6PD) deficient subjects are vulnerable to oxidative stress. Quercetin, a flavonoids, has been employed as a potent oxygen-free radical scavenger in order to assess the protective effects of quercetin against H2O2-induced oxidative damage in G6PD-deficient and normal human erythrocytes. Erythrocytes of G6PD-deficient (n = 10) and normal (n = 10) subjects were ...

متن کامل

Protective Effect of Quercetin on Oxidative Stress in Glucose-6-Phosphate Dehydrogenase-Deficient Erythrocytes in Vitro

Glucose-6-phosphate dehydrogenase (G6PD) deficient subjects are vulnerable to oxidative stress. Quercetin, a flavonoids, has been employed as a potent oxygen-free radical scavenger in order to assess the protective effects of quercetin against H2O2-induced oxidative damage in G6PD-deficient and normal human erythrocytes. Erythrocytes of G6PD-deficient (n = 10) and normal (n = 10) subjects were ...

متن کامل

INHIBITION OF HUMAN ERYTHROCYTE GLUCOSE 6-PHOSPHATE DEHYDROGENASE ACTIVITY BY DEHYDROEPIANDROSTERONE AND RELATED STEROIDS.

The inhibitory effects of several steroids on G6PD activity using intact erythrocytes are reported. Incubation of whole blood with dehydroepiandrosterone (DHEA) resulted in 42% and 12% inhibition in the enzyme activity in the presence and absence of oxygen, respectively. Addition of epinephrine and/or aminophylline into the incubation medium caused further enzyme inhibition suggesting a po...

متن کامل

Molecular Characterization of Cosenza Mutation among Patients with Glucose-6-Phosphate Dehydrogenase Deficiency in Khuzestan Province, Southwest Iran

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is one of the most common hereditary enzymatic disorders in human, increases the vulnerability of erythrocytes to oxidative stress. It is also characterized by remarkable molecular and biochemical heterogeneity. According to previous investigations, G6PD Cosenza (G1376C) is a common G6PD mutation in some parts of Iran. Therefore in the present...

متن کامل

Biochemical mechanisms of glucose-6-phosphate dehydrogenase deficiency.

A solid-phase radioimmunoassay for human glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP+ 1-oxidoreductase; EC 1.1.1.49) was developed that allowed the specific activity of this enzyme protein to be measured in lysates from whole erythrocyte populations, in lysates from erythrocytes of different ages, and in purified samples. The enzyme was highly purified from erythrocytes of si...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Methods in enzymology

دوره 41  شماره 

صفحات  -

تاریخ انتشار 1975