A non-radioactive and two radioactive assays for selenophosphate synthetase activity.
Selenophosphate synthetase catalyzes the formation of monoselenophosphate (SePO3(3-)) from ATP and selenide (reaction 1). [formula: see text] In one assay frequently used, [8-14C]AMP formation from [8-14C]ATP is estimated after separation of the nucleotides by thinlayer chromatography. An alternative non-radioactive assay in which the AMP product is estimated using AMP deaminase is described. The highly oxygen-labile selenophosphate product can be estimated in an assay employing [gamma-32P]ATP. The 32P-labeled selenophosphate is converted to [32P]orthophosphate by treatment with iodine and estimated after removal of residual [32P]ATP on charcoal.
Liu
S Y
SY
Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Stadtman
T C
TC
D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D001426:Bacterial Proteins / Q000032:analysis* / Q000378:metabolism*; D002250:Carbon Radioisotopes; D002855:Chromatography, Thin Layer; D003124:Colorimetry; D029721:Drosophila Proteins; D004926:Escherichia coli / Q000201:enzymology; D010710:Phosphates / Q000378:metabolism; D010761:Phosphorus Radioisotopes; D010770:Phosphotransferases; D012643:Selenium / Q000378:metabolism; D018036:Selenium Compounds / Q000378:metabolism
D001426:Bacterial Proteins; D002250:Carbon Radioisotopes; D029721:Drosophila Proteins; D010710:Phosphates; D010761:Phosphorus Radioisotopes; D018036:Selenium Compounds; C076818:selenophosphate; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D010770:Phosphotransferases; C062762:selenophosphate synthetase; D012643:Selenium