Biomaterial Database

Labeling of a specific arginine residue at the active site of glutamine synthetase (E.coli). 1985

J A Colanduoni, and J J Villafranca

Chemical modification of a specific arginine residue of Escherichia coli glutamine synthetase has been accomplished by the use of the arginine-specific reagents p-hydroxyphenylglyoxal, phenylglyoxal, and methylglyoxal. Modification of one arginine residue results in complete inactivation of the enzyme and the modified enzyme seems to be extremely stable since no reactivation is observed upon addition of free arginine or dialysis. Saturating levels of ATP but not L-glutamate, L-methionine sulfoximine, or inorganic phosphate provide substantial protection against inactivation of the enzyme suggesting the modified amino acid is at or near the ATP substrate binding site. However, an ATP affinity analog is not prevented from binding upon modification of the arginine residue indicating that the reduction in catalytic activity is not solely due to alteration in substrate binding but may also reflect a catalytic role for the arginine residue.

UI	MeSH Term	Description	Entries
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D010658	Phenylglyoxal	A reagent that is highly selective for the modification of arginyl residues. It is used to selectively inhibit various enzymes and acts as an energy transfer inhibitor in photophosphorylation.
D011765	Pyruvaldehyde	An organic compound used often as a reagent in organic synthesis, as a flavoring agent, and in tanning. It has been demonstrated as an intermediate in the metabolism of acetone and its derivatives in isolated cell preparations, in various culture media, and in vivo in certain animals.	Acetylformaldehyde,Methylglyoxal,Oxopropanal,Pyruvic Aldehyde,Aldehyde, Pyruvic
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005974	Glutamate-Ammonia Ligase	An enzyme that catalyzes the conversion of ATP, L-glutamate, and NH3 to ADP, orthophosphate, and L-glutamine. It also acts more slowly on 4-methylene-L-glutamate. (From Enzyme Nomenclature, 1992) EC 6.3.1.2.	Glutamine Synthetase,Glutamate Ammonia Ligase (ADP),Glutamate Ammonia Ligase,Ligase, Glutamate-Ammonia,Synthetase, Glutamine
D001120	Arginine	An essential amino acid that is physiologically active in the L-form.	Arginine Hydrochloride,Arginine, L-Isomer,DL-Arginine Acetate, Monohydrate,L-Arginine,Arginine, L Isomer,DL Arginine Acetate, Monohydrate,Hydrochloride, Arginine,L Arginine,L-Isomer Arginine,Monohydrate DL-Arginine Acetate
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor