title: 65-kilodalton protein phosphorylation in human peripheral blood eosinophils.
abstract: To evaluate the presence of protein phosphorylation in peripheral blood eosinophils, venous blood was drawn from normal healthy volunteers. Eosinophils were isolated on a Percoll gradient and were incubated with [gamma32P]ATP in the presence of Mg2+. After stopping the reaction, SDS-PAGE was performed and autoradiographs were prepared to determine the incorporation of 32P into proteins. Eosinophils developed at least 24 protein bands below 116.25 kD by SDS-PAGE. In the autoradiographs, one distinct radioactive band was observed with a molecular weight of 65 kD. 32P incorporation into the 65-kD band was dependent on Mg2+ concentration and maximal response was observed at concentrations of 2-6 mM MgCl2. 32P incorporation into the band was dependent on the reaction time and temperature of the reaction system. Acid hydrolysis showed that [32P]phosphate radioactivity in the cells was present primarily as phosphoserine, indicating the presence of 65-kD protein phosphorylation in human peripheral blood eosinophils.
authors.affiliation: Department of Dermatology, Gunma University School of Medicine, Maebashi, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kurosawa
authors.forename: Y
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Y
authors.initials: Y
authors.lastname: Igarashi
authors.forename: H
authors.initials: H
authors.lastname: Amano
authors.forename: N
authors.initials: N
authors.lastname: Kanbe
authors.forename: Y
authors.initials: Y
authors.lastname: Matsushima
authors.forename: O
authors.initials: O
authors.lastname: Ishikawa
authors.forename: Y
authors.initials: Y
authors.lastname: Miyachi
mesh_terms: D000328:Adult; D001798:Blood Proteins / Q000378:metabolism*; D004804:Eosinophils / Q000378:metabolism*; D005260:Female; D006801:Humans; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D019606:Phosphoamino Acids / Q000032:analysis; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D013696:Temperature
chemical_list: D001798:Blood Proteins; D019606:Phosphoamino Acids; D010750:Phosphoproteins; D008274:Magnesium