Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published October 1, 1951 | public
Journal Article Open

The L-amino acid oxidase of Neurospora


In 1944 one of us described a D-amino acid oxidase in extracts of Neurospora crassa (1). Except for slight activity against L-glutamate, no oxidation of L-amino acids was observed. Recently a means for inducing the formation of a soluble L-amino acid oxidase by the mold was reported by Bender, Krebs, and Horowitz (2). This is accomplished by reducing the biotin content of the basal medium (3) from the 5 γ per liter usually employed to 0.25 γ per liter. When cultured in such a medium, Neurospora produces an active L-amino acid oxidase which can be demonstrated both in extracts and in the medium. Reduction of the biotin level produces no effect on the D-amino acid oxidase, which is still found in extracts but not in the culture medium. The activity of the L-oxidase toward thirty-eight amino acids has been investigated by Bender and Krebs (4). The initial purpose of the present investigation was to explore certain possibilities for a genetic study of the enzyme. Of special interest was the fact, cited by Bender et al. (a), that the oxidase could not be detected in all of the wild type strains tested. The question arose as to whether this is due to the genetic inability of certain strains to form the enzyme. In connection with the investigation of this problem a general survey of the properties of the enzyme was carried out, together with a preliminary study of the mechanism of the biotin effect and of the adaptive formation of the enzyme. The results of these studies are reported below. Simultaneously with our investigation and independently of it, Dr. K. Burton (5), working in Professor Krebs' laboratory, has carried out a study of the Neurospora L-amino acid oxidase. Where our respective studies overlap mutual confirmation was obtained in most essential points. We wish to thank Dr. Burton for permission to read his manuscript before publication.

Additional Information

Copyright © 1951 by the American Society for Biochemistry and Molecular Biology. (Received for publication, June 2, 1951) These studies were aided by a contract between the Office of Naval Research, United States Navy Department, and the California Institute of Technology (NR-16-4010). [P.S.T. was a] Predoctoral Research Fellow of the National Institutes of Health, United States Public Health Service, 1949-1951.


Files (814.9 kB)
Name Size Download all
814.9 kB Preview Download

Additional details

August 21, 2023
October 16, 2023