1. Cyclic 3′,5′-Nucleotide Phosphodiesterase in Rat Skin II. Biochemical Characterization
- Author
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Ken Hashimoto, Lloyd E. King, and Solomon S. Solomon
- Subjects
Male ,Adenosine monophosphate ,Time Factors ,Epinephrine ,Hydrocortisone ,Dermatology ,In Vitro Techniques ,Tritium ,Biochemistry ,Divalent ,chemistry.chemical_compound ,Centrifugation, Density Gradient ,Cyclic AMP ,medicine ,Animals ,Magnesium ,Nucleotide ,Cyclic GMP ,Molecular Biology ,Edetic Acid ,Skin ,Gel electrophoresis ,chemistry.chemical_classification ,Manganese ,Bucladesine ,Phosphoric Diester Hydrolases ,Phosphodiesterase ,Cell Biology ,Hydrogen-Ion Concentration ,Adenosine Monophosphate ,Rats ,Adenosine Diphosphate ,Kinetics ,Adenosine diphosphate ,Enzyme ,chemistry ,3',5'-Cyclic-AMP Phosphodiesterases ,Electrophoresis, Polyacrylamide Gel ,medicine.drug - Abstract
The biochemical characteristics of cyclic 3',5'-nucleotide phosphodiesterase were studied in homogenates of male albino rat skin using preparations which were predominantly epidermal. Enzymatic activity was detected in both the particulate and soluble fractions of these skin homogenates. Two kinetically distinct phosphodiesterase (PDE) activities were detected in the soluble fraction (100,000 times g supernatant). This 100,000 times g supernatant contains at least two distinct protein bands that hydrolyze cyclic AMP as demonstrated by gel electrophoresis. Divalent cations (Mg-++ or Mn-++) and 2-mercaptoethanol were required for maximal enzymatic activity. Epinephrine, dibutyryl cyclic AMP, and methylxanthines inhibited while imidazole and histamine phosphate stimulated the cyclic AMP phosphodiesterase activity at high and low cyclic AMP concentrations. Cyclic GMP competitively inhibited hydrolysis of low, but not high, concentrations of cyclic AMP. Hydrocortisone phosphate in pharmacologic concentrations blocked PDE denaturation by heat. These studies indicate that there are complex interrelationships between cyclic nucleotides and PDE in rat skin.
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