title: Tissue specificity of human phosphodiesterase. I. Blood serum.
abstract: Human blood serum was found to contain two enzymes which hydrolyze various phosphate diester and phosphonate ester bonds. The enzymes were isolated by butanol extraction, ammonium sulfate precipitation, column chromatography and gel electrophoresis. Zymograms showed that one of these enzymes is serum alkaline phosphatase and the other is a 'true' phosphodiesterase I. Serums of 25 persons showed no polymorphisms for either activity. Alkaline phosphatase hydrolyzes phenolic thymidine 5'-nucleotide esters readily, but phenylphosphonate esters very poorly. Serum phosphodiesterase I prefers phenylphosphonate esters to nucleotide diesters, and has no detectable monoesterase activity.
mesh_terms: D002848:Chromatography, DEAE-Cellulose; D005456:Fluorescent Dyes; D006801:Humans; D009439:Neuraminidase; D043264:Phosphodiesterase I; D010727:Phosphoric Diester Hydrolases / Q000097:blood / Q000302:isolation & purification*
chemical_list: D005456:Fluorescent Dyes; D010727:Phosphoric Diester Hydrolases; D043264:Phosphodiesterase I; D009439:Neuraminidase