title: [Determination of riboflavin kinase activity in yeast].
abstract: It is established that the main reason of the riboflavin kinase (RFK, EC 2.7.1.26) low specific activity in the cell-free extracts of the yeast Pichia guillermondii Wickerham ATCC 9058 is the presence of alkaline phosphatase (EC 3.1.3.1), effectively destructing flaven mononucleotide. By chromatography of the cell-free extracts of P. guillermondii on DEAE-Sephadex A-50, CM-Sphadex C-50, CM-cellulose, Sephadexes G-75 and G-100 RFK and alkaline phosphatase may be separated completely. Any of these procedures results in a several times increase of the RFK activity as compared with the initial preparation. One failed to obtain a similar effect by fractionation of the extracts with amminium sulphate and by hydroxylapatite chromatography. A simple method is developed for determining the activity of RFK in the cell-free extracts of yeast on the basis of negative adsorption of this enzyme on DEAE-Sephadex A-50. A selective inhibition of alkaline phosphatase by ions Be2+ and F- yields a less satisfactory result. The data are presented on the PFK activity of certain species of flavinogenic (Pichia guillermondii, Torulopsis camdida) and non-flavinogenic (Pichia ohmeri, Candida utilis, Saccharomyces cervisiae) yeast.
mesh_terms: D000469:Alkaline Phosphatase / Q000302:isolation & purification / Q000378:metabolism; D001203:Ascomycota / Q000201:enzymology*; D001608:Beryllium / Q000494:pharmacology; D010770:Phosphotransferases / Q000302:isolation & purification / Q000378:metabolism*; D010843:Pichia / Q000201:enzymology*; D012256:Riboflavin / Q000378:metabolism; D013045:Species Specificity
chemical_list: D010770:Phosphotransferases; D000469:Alkaline Phosphatase; D001608:Beryllium; D012256:Riboflavin