Disease relevance of N-GLYCYLGLYCINE

• AT-125 blocked and glycylglycine potentiated DCVG toxicity, indicating that metabolism by gamma-glutamyltransferase is required [1].
• In the dark, the dipeptide is a reversible inhibitor of glycylglycine uptake by live E. coli W cells [2].
• The potential for the development of resistance in oxacillin-resistant Staphylococcus aureus (ORSA) to lysostaphin, a glycylglycine endopeptidase produced by Staphylococcus simulans biovar staphylolyticus, was examined in vitro and in an in vivo model of infection [3].
• 1. Intestinal absorption of glycylglycine was studied in four control subjects and six patients with tropical sprue by using a direct technique of intestinal perfusion [4].
• The production levels, hydrolytic and bacteriocidal activities of the Listeria monocytogenes bacteriophage N-acetylmuramoyl-l-alanine amidase endolysin Ply511 and the glycylglycine endopeptidase lysostaphin were examined [5].

High impact information on N-GLYCYLGLYCINE

• The purified enzyme displayed a V(max) of 7 units mg(-)1 of protein for fructose 6-phosphate cleavage (at 30 degrees C, pH 8.5 in 50 mm glycylglycine buffer) [6].
• Although 32% of the wild-type hydrolysis activity was retained in this mutant, the activity could not be enhanced by addition of an acceptor substrate, glycylglycine, indicating that the transpeptidation reaction was specifically prevented [7].
• 5. In contrast, acyl group transfer from cathepsin B to glycylglycine and L-leucylglycine depended on a group with a pKa of about 4 [8].
• Limited tryptic digestion of active ubiquitin yields the inactive, later eluting form and the dipeptide glycylglycine [9].
• We have used a stopped flow rapid reaction pH apparatus to investigate the carbamate equilibrium in glycylglycine solutions and in three biological tissues, human plasma, sheep muscle, and sheep brain, as well as to investigate the kinetics of carbamate formation in glyclyglycine solution and in human plasma [10].

Chemical compound and disease context of N-GLYCYLGLYCINE

• When intact E. coli cells are photolyzed at approximately 350 nm in the presence of the photolabile dipeptide, their ability to transport either glycylglycine or unphotolyzed glycyl-4-azido-2-nitro-L-phenylalanine is irreversibly inhibited, but their ability to transport arginine is unaffected [2].
• To investigate this notion further, intracellular accumulation and cytotoxicity of DXR coupled to several small peptides, such as glycylglycine (diGly), glycylglycylglycine (triGly), reduced glutathione (GSH) and oxidized glutathione (GSSG), were investigated using DXR-sensitive (AH66P) and DXR-resistant (AH66DR) rat hepatoma cell lines [11].

Biological context of N-GLYCYLGLYCINE

• Difference spectra of the acylation of chymotrypsin by glycylglycine p-nitrophenyl ester have been obtained by averaging ten stopped-flow shots and show good signal-to-noise ratio without smoothing [12].
• The density of [125I]iodoclonidine binding sites in glycylglycine buffer was similar to that labeled by [3H]RX821002 [13].
• The two intermediate radicals, deamination and H-abstraction radicals, were produced in the initial interactions of glycylglycine with reactive species (e-aq, OH, H) formed in H2O [14].
• Although glycylglycine exists mainly in the zwitterionic form at pH 7.30, it induced marked depolarization in the membrane potential and reduction in the input resistance both in the presence and absence of Na+ in the medium [15].

Anatomical context of N-GLYCYLGLYCINE

• It is concluded that the intestinal mucosa has much less hydrolase activity for carnosine than for glycylglycine and other dipeptidases, and the relatively slow hydrolysis appears to be the rate-limiting step in the total absorptive process [16].
• It is concluded that the fraction of lysostaphin active in cell lysis, believed to be a glycylglycine endopeptidase with a molecular weight of about 25,000, passes freely through the capsular layer to its target in the staphylococcal cell wall [17].
• Glycylglycine also stimulated the GGT activity in the astroglia more (4-fold) than in cortical capillaries or synaptosomes (3-fold) [18].
• Effect of hydrogen ion-gradient on carrier-mediated transport of glycylglycine across brush border membrane vesicles from rabbit small intestine [19].
• The properties of carnosine (Car) and glycylglycine (Gly-Gly), transported across the mucosal border, were studied in isolated guinea pig everted ileum [20].

Associations of N-GLYCYLGLYCINE with other chemical compounds

• In the absence of maleate, the enzyme catalyzes the utilization of glutamine (by conversion to gamma-glutamylglutamine, glutamate, and ammonia) at about 2% of the rate observed for catalysis of transpeptidation between glutathione and glycylglycine; the utilization of glutamine occurs about 8 times more rapidly in the presence of 0.1 M maleate [21].
• In this investigation, we studied with RSM the change in the measured activity of gamma-glutamy-transferase (EC 2.3.2.2) as a function of changes in concentrations of donor (gamma-glutamyl-3-carboxy-4-nitroanilide) acceptor (glycylglycine), and pH [22].
• A theoretical study of potassium cation binding to glycylglycine (GG) and alanylalanine (AA) dipeptides [23].
• The observed pseudo-first-order rate constants (k(obs)) and rate enhancing factors (REF) were as follows: 4.1x10(-3 )h(-1)(REF=23) for GylGly, 1.6x10(-3 )h(-1)(REF=21) for GlyLeu, 5.1x10(-3 )h(-1)(REF=64) for LeuGly and 9.2x10(-2 )h(-1)(REF=47) for GlySer [pH 8.1, dipeptide 2 mM, copper(II) 2 mM and TACH 2 mM] [24].
• The apparent Km values for glutathione and gamma-glutamyl-p-nitroanilide as gamma-glutamyl donors in the transpeptidation reaction were both 35 microM, and those for glycylglycine and L-arginine as acceptors were 0.59 and 0.21 M, respectively [25].

Gene context of N-GLYCYLGLYCINE

• Lack of significant effect of L(+)-glutamate on serum gamma-glutamyltransferase activity determined in the presence of glycylglycine [26].
• The presence of glycylglycine in the medium during photolysis protects the cells against the light-dependent inactivation of dipeptide transport [2].
• No increase in gamma-glutamyltransferase activity determined in human sera at 25, 30, or 37 degrees C could be demonstrated when L(+)-glutamate, 10 to 5000 mumol/liter, was incorporated into reaction media containing glycylglycine, 40 mmol/liter [26].
• Staphylococcus simulans biovar staphylolyticus produces an extracellular glycylglycine endopeptidase (lysostaphin) that lyses other staphylococci by hydrolyzing the cross bridges in their cell wall peptidoglycans [27].
• Quantum chemical and RRKM calculations were carried out on protonated glycylglycine in order to determine the atomic details of the main fragmentation pathways leading to formation of a1 and y1 ions [28].

Analytical, diagnostic and therapeutic context of N-GLYCYLGLYCINE

• Using a double-lumen tube jejunal perfusion system in vivo, the mutual effects of carnosine (beta-alanyl-L-histidine) and glycylglycine on their respective absorption rates have been studied in six Zambian African adults [29].
• The hydrolysis of glycylglycine (GylGly), glycyl-L-leucine (GlyLeu), L-leucylglycine (LeuGly) and glycyl-DL-serine (GlySer) promoted by a copper(II)- cis, cis-1,3,5-triaminocyclohexane complex [Cu(II)TACH] was investigated at 70 degrees C and pH 7-10, using HPLC [24].
• The glycylglycine/glycine/glucose electrolyte solution was found to be suitable for rehydration, but not to have an advantage over the standard WHO/ORS [30].
• A value of 2.7 was obtained by the ultracentrifugation method for glycylglycine in phosphate buffer at 0.1 ionic strength and pH 6.8 at 10 degrees C. For both glycine and glycylglycine, K increases when the ionic strength of the phosphate buffer is decreased [31].
• Further solutions of the above-mentioned problem were the on-line preparation of bicarbonate fluids for intermittent peritoneal dialysis, the addition of bicarbonate just before use, the combination of bicarbonate with organic acids, or its combination with the dipeptide glycylglycine as a stabilizing agent [32].

References