Worm Breeder's Gazette 4(1): 29
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
The flu-2 X mutants are characterized by a dull greenish-yellow autofluorescence of the gut cells and have only 5-6% of the wild type kynureninase activity (Babu, P., 1974, Mol. Gen. Genet. 135, 39-44). We have partially purified kynureninase from wild type animals about 60 fold over the crude extract by ammonium sulphate precipitation, chromatography on Sephadex G-150, DEAE cellulose, and affinity chromatography on L-kynurenine bound to Sepharose. The molecular weight of the partially purified enzyme as estimated on the basis of its elution profile from the Sephadex G-150 column is about 56,000. The enzyme requires pyridoxal-5'-phosphate as coenzyme and the pH optimum is at pH 8.0 in phosphate or Tris-HCl buffer. One of the alleles of the flu-2 gene flu-2(t201) has about 15% wild type enzyme activity. Thermal stability tests were carried out on the partially purified enzymes from wild type and the (t201) mutant. The two enzymes have different heat stabilities at 60 C. The t 1/2 for the wild type enzyme is 3.5 minutes and for the T201 enzyme is 2.5 minutes. This suggests that the two enzymes could be structurally different. Experiments in Gottingen are in progress using some of the X-chromosome duplications, isolated by Bob Herman, which include the flu-2 region. We want to look whether there is a gene dosage effect, which would indicate that flu-2 may be the structural gene for the enzyme kynureninase (EC.184.108.40.206).