Y-Glutamyl kinase

L-Pro <3, 4, 5> (<3> enzyme from strain PAOl 5mM, 50% inhibition, complete inhibition at 30 mM, noncompetitive. Strain PAO 879, a proline-auxo-troph mutant lacks a proline-inhibitable y-glutamyl kinase [5] <4> 150 = 0.08 mM, at room temperature. At low temperatures the inhibition switches over into allosteric activation and the biosynthesis of proline is started [7] <4> feedback-inhibition [8]) [5, 7, 8, 10]... 

Additional information <2, 3> (<2> the concentration of glutamate which yields half-maximal activity is 33 mM for y-glutamyl kinase DHPr, and 37mM for y-glutamyl kinase w-l-, no typical Michealis-menten kinetics [2] <3> plots of the enzyme activity as a function of ATP concentration are non-hyperbolic [5]) [2, 5]... 

D192G <1> (<1> the mutation causes an enhanced feedback-resistant y-glutamyl kinase activity and conferrs an analogue-resistant phenotype to an Escherichia coli transformant containing the mutated gene [1]) [1]... 

Massarelli, L Forlani, G. Ricca, E. De Felice, M. Enhanced and feedback-resistant y-glutamyl kinase activity of an Escherichia coli transformant carrying a mutated proB gene of Streptococcus thermophilus. FEMS Microbiol. Lett., 182, 143-147 (2000)... 

Smith, C.J. Deutch, A.H. Rushlow, K.E. Purification and characteristics of a y-glutamyl kinase involved in Escherichia coli proline biosynthesis. J. Bacteriol., 157, 545-551 (1984)... 

Krishna, R.V. Leisinger, T. Biosynthesis of proline in Pseudomonas aeruginosa. Partial purification and characterization of y-glutamyl kinase. Biochem. J., 181, 215-222 (1979)... 

Fujita, T, Maggio, A, Garcia-Rios, M. Stauffacher, C. Bressan, R.A, Cson-ka, L.N, Identification of regions of the tomato y-glutamyl kinase that are involved in allosteric regulation by proline. J. Biol. Chem., 278, 14203-14210 (2003)... 

Morita, Y. Nakamori, S, Takagi, H. L-proline accumulation and freeze tolerance of Saccharomyces cerevisiae are caused by a mutation in the PROl gene encoding y-glutamyl kinase. Appl. Environ. Microbiol., 69, 212-219 (2003)... 

Meijer, P.-J. Lilius, G, Holmberg, N. Bulow, L. An artificial bifunctional enzyme, y-glutamyl kinase/y-glutamyl phosphate reductase, improves NaCl tolerance when expressed in Escherichia coli. Biotechnol. Lett, 18, 1133-1138 (1996)... 

Enzymes, measured in clinical laboratories, for which kits are available include y-glutamyl transferase (GGT), alanine transferase [9000-86-6] (ALT), aldolase, a-amylase [9000-90-2] aspartate aminotransferase [9000-97-9], creatine kinase and its isoenzymes, galactose-l-phosphate uridyl transferase, Hpase, malate dehydrogenase [9001 -64-3], 5 -nucleotidase, phosphohexose isomerase, and pymvate kinase [9001-59-6]. One example is the measurement of aspartate aminotransferase, where the reaction is followed by monitoring the loss of NADH ... 

Seddon, A.P. Zhao, K.Y. Meister, A. Activation of glutamate by y-gluta-mate kinase formation of y-cis-cycloglutamyl phosphate, an analog of y-glutamyl phosphate. J. Biol. Chem., 264, 11326-11335 (1989)... 

Cyclins Protein kinase A Tryptophan oxygenase y-Glutamyl transferase... 

ARG5,6 Protein that is processed in the mitochondrion to yield acetylglutamate kinase and N-acetyl-y-glutamyl-phosphate reductase, which catalyze the second and third steps in arginine biosynthesis enzymes form a complex with Arg2p... 

Oxidation of thiols in proteins is often involved in regulation of enzyme activity, such as glucose-6-phosphate dehydrogenase, pyruvate kinase, brain adenylate cyclase, y-glutamyl-synthetase and others (Elstner, 1990) Carbonyl compounds can be attacked by amino groups. In-... 

Phosphorylation occurs in the Golgi membranes of the mammary cell, catalysed by two serine-specific casein kinases. Only certain serines are phosphorylated the principal recognition site is Ser/Thr.X.Y, where Y is a glutamyl and occasionally an aspartyl residue once a serine residue has been phosphorylated, SerP can serve as a recognition site. X may be any amino acid but a basic or a very bulky residue may reduce the extent of phosphorylation. However, not all serine residues in a suitable sequence are phosphorylated, suggesting that there may be a further topological requirement, e.g. a surface location in the protein conformation. 

Phosphoroglycerate kinase catalyses the transfer of a phosphoryl residue from 1,3-bisphosphoroglycerate (29), a constituent of the glycolytic pathway, to ADP. It had been postulated that an intermediate in this reaction was a phosphoryl enzyme in which the phosphoryl group was attached to the y-carboxy-group of a glutamyl residue. Recent studies, however, show that the phosphoryl enzyme contains a stoicheiometric amount of (29), and hence is probably a tightly bound (but not covalently linked) complex of the kinase and (29). 

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