Immunochemical characterization of glutamine synthetase from Neurospora crassa glutamine auxotrophs.
AUTOR(ES)
Sánchez, F
RESUMO
Glutamine synthetase derived from two Neurospora crassa glutamine auxotrophs was characterized. Previous genetic studies indicated that the mutations responsible for the glutamine auxotrophy are allelic and map in chromosome V. When measured in crude extracts, both mutant strains had lower glutamine synthetase specific activity than that found in the wild-type strain. The enzyme from both auxotrophs and the wild-type strain was partially purified from cultures grown on glutamine as the sole nitrogen source, and immunochemical studies were performed in crude extracts and purified fractions. Quantitative rocket immunoelectrophoresis indicated that the activity per enzyme molecule is lower in the mutants than in the wild-type strain; immunoelectrophoresis and immunochemical titration of enzyme activity demonstrated structural differences between the enzymes from both auxotrophs. On the other hand, the monomer of glutamine synthetase of both mutants was found to be of a molecular weight similar to that of the wild-type strain. These data indicate that the mutations are located in the structural gene of N. crassa glutamine synthetase.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=216901Documentos Relacionados
- Genetics and physiology of Neurospora crassa glutamine auxotrophs.
- Genetic and biochemical characterization of glutamine synthetase from Neurospora crassa glutamine auxotrophs and their revertants.
- Oxidation of Neurospora crassa glutamine synthetase.
- Isolation and characterization of a Neurospora crassa mutant altered in the alpha polypeptide of glutamine synthetase.
- Nitrogen source regulates glutamine synthetase mRNA levels in Neurospora crassa.