In vitro reconstitution of nitrate reductase activity of the Neurospora crassa mutant nit-1: specific incorporation of molybdopterin.

Journal Article (Journal Article)

The reduced, metal-free pterin of the molybdenum cofactor has been termed molybdopterin. Oxidation of any molybdopterin-containing protein in the presence or absence of iodine yields oxidized molybdopterin derivatives termed Form A and Form B, respectively. Application of these procedures to whole cells and cell extracts has demonstrated the presence of molybdopterin in wild-type Neurospora crassa, and its absence in the cofactor-deficient mutant nit-1. In order to demonstrate that the reconstitution of nitrate reductase activity in nit-1 extracts results from the incorporation of molybdopterin into the apoprotein, active molybdopterin, free of contaminating amino acids or peptides, was isolated from chicken liver sulfite oxidase and used in the reconstitution system. The results show that, during reconstitution, exogenous molybdopterin is specifically incorporated into the nitrate reductase protein, confirming the role of molybdopterin as the organic moiety of the molybdenum cofactor.

Full Text

Duke Authors

Cited Authors

  • Kramer, S; Hageman, RV; Rajagopalan, KV

Published Date

  • September 1, 1984

Published In

Volume / Issue

  • 233 / 2

Start / End Page

  • 821 - 829

PubMed ID

  • 6237611

International Standard Serial Number (ISSN)

  • 0003-9861

Digital Object Identifier (DOI)

  • 10.1016/0003-9861(84)90511-3


  • eng

Conference Location

  • United States