| abstract |
Methods are described for screening for the presence or absence of inhibition of the activity of enzymes participating in riboflavin biosynthesis. GTP cyclohydrolase II activity is determined through the extent of conversion of GTP to 2,5-diamino-6-ribosylamino-4(3H)-pyrimidinone 5'-phosphate, catalysed by a protein having a GTP cyclohydrolase II sequence. The activity of 3,4-dihydroxy-2-butanone 4-phosphate synthase activity is detected through the extent of conversion of ribulose 5-phosphate to 3,4-dihydroxy-2-butanone 4-phosphate, catalysed by a protein having a 3,4-dihydroxy-2-butanone 4-phosphate synthase sequence. |