title: Chromium-associated 32P-labeling of proteins.
abstract: The incubation of proteins with chromium (Cr3+ or Cr6+) in the presence of 32P ([gamma-32P]ATP or H3(32)PO4) at room temperature for 10-30 min resulted in the labeling of these proteins with 32P. The 32P-labeled proteins could be separated by SDS-polyacrylamide gel electrophoresis and identified by exposure to X-ray film. The characteristics of this procedure included: the optimal chromium concentration was 100 microM; the minimum requirement of each protein was 1 microgram; the optimal pH value was between 6 and 8; metal ions such as V5+, Mn2+ and Fe3+ strongly inhibited the effect of chromium, whereas Ca2+ and Mg2+ had little effect. It was concluded that chromium binds to the proteins and forms a complex with 32P to achieve the 32P-labeling of the proteins. This technique can be applied for the rapid preparation of 32P labels on protein markers for gel electrophoresis and for the identification of unknown protein species.
mesh_terms: D001345:Autoradiography; D002021:Buffers; D002118:Calcium / Q000494:pharmacology; D002850:Chromatography, Gel; D002857:Chromium / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005290:Ferric Compounds / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007553:Isotope Labeling / Q000379:methods*; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D008970:Molecular Weight; D010758:Phosphorus / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism*; D013997:Time Factors; D014800:Vitallium / Q000494:pharmacology
chemical_list: D002021:Buffers; D005290:Ferric Compounds; D011506:Proteins; D002857:Chromium; D014800:Vitallium; D010758:Phosphorus; D008345:Manganese; D008274:Magnesium; D002118:Calcium