Involvement of sulphydryl groups in glutamine synthetase activity fromRhodobacter capsulatusE1F1

Assay for glutamine synthetase activity.

The use of phosphoenolpyruvate plus pyruvate kinase as an ATP-generating system in the assay for glutamine synthetase activity via the formation of gamma-glutamylhydroxamate from glutamate and hydroxylamine with crude tissue preparations is shown to give values far in excess of the true glutamine synthetase activity of the tissue. This is due to the generation of pyruvate, which reacts with hyd...

Regulation of synthesis of glutamine synthetase by adenylylated glutamine synthetase.

We have examined three mutants of Klebsiella aerogenes whose genetic lesions (glnB, glnD, and glnE) are in loci unlinked to the structural gene for glutamine sythetase (glnA) and in which the control of both the level and state of adenylylation of glutamine synthetase is altered. Each mutation alters a different component of the adenylylation system of glutamine synthetase [L-glutamate:ammonia ...

Clonal Differences in Glutamine Synthetase Activity of Hepatoma Cells

Most hepatomas contain only traces of glutamine synthetase (GS) although they originate from liver which has high levels of the enzyme (1-3) The H T C cell line which was derived from Morris Hepa toma 7288C retained certain characteristics of liver cells, notably the induction of tyrosine amino transferase (4, 5), while other liver characteristics, among them GS activity, could not be detected ...

Biochemical and molecular analysis of glutamine synthetase gene in brassica napus L.

The sulphydryl groups of sickle-cell haemoglobin.

particularpH owing to the screening ofthe haematin iron atom from the influence of the various ionizing groups. On this basis a larger critical I would signify that a larger concentration of salt ions is required for complete screening, and hence that there is a stronger interaction between the iron and the ionizing groups in MetHb. In conclusion, although the mechanism may be different it may ...