Accession Number:

AD0416136

Title:

ENZYMATIC FORMATION OF D-KYNURENINE

Descriptive Note:

Corporate Author:

ARMY BIOLOGICAL LABS FREDERICK MD

Personal Author(s):

Report Date:

1963-08-01

Pagination or Media Count:

18.0

Abstract:

A study of the enzyme system responsible for D tryptophan conversion to D-kynurenine showed that a dialyzed supernatant fraction ca. 20,000g prepared from homogenates of rabbit intestinal mucosa was capable of converting D-tryptophan in the presence of air, Mg 10 to the -3 power M, adenosine 5 x 10 to the -3 power M, and methylene blue 10 to the -4 power M to stoichiometric amounts of D-kynurenine. The enzyme activity was evident only in parts of the small intestines corresponding to the terminal 30 per cent of the organ adjacent to the colon. The product was identified as kynurenine by paper chromatography, absorption spectrum, and quantitation of UV optical density measurements in agreement with aromatic amine assay by the Bratton-Marshall method. The D-configuration was assigned primarily on the basis of results of chromatography by the proce dure of Price and Dodge 1956, which distinguishes the D- and L-isomers of kynurenine. Methylene blue appeared essential for the reaction FAD, FMN, DPN, TPN, or ferricyanide could not replace the dye. Adenosine could be replaced by ATP, 5AMP, and 3, 5cycle AMP, but not by adenine. The presence of added catalase was stimulatory for kynurenine formation, whereas the presence of an H2O2 generating system L amino acid oxidase and L-leucine did not substitute for the methylene blue.

Subject Categories:

  • Biochemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE