Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “GLYCINE”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed1986

Acyl-CoA: glycine N-acyltransferase: in vitro studies on the glycine conjugation of straight- and branched-chained acyl-CoA esters in human liver.

Apparent kinetic constants (Km and Vmax values) were determined for human liver acyl-CoA: glycine acyltransferase (glycine-N-acylase) towards isobutyryl-CoA, 2-methyl butyryl-CoA, isovaleryl-CoA, butyryl-CoA, hexanoyl-CoA, octanoyl-CoA, and decanoyl-CoA. These acyl-CoA esters were selected because of their relevance to the human diseases with cellular accumulation of these esters, i.e., especially to metabolic defects in the acyl-CoA dehydrogenation steps of the branched-chain amino acids, lysine, 5-hydroxy lysine, tryptophan, and fatty acid oxidation pathways. With the acyl-CoA ester as the fixed substrate, the Km value for glycine ranged from 0.5 to 2.9 mole/liter, and with glycine as fixed substrate, the Km values for the acyl-CoA esters varied from 0.3 to 5.6 mmole/liter. It is concluded that the substrate concentration is decisive for the glycine conjugate formation and that the occurrence in urine of acylglycines reflects an intramitochondrial accumulation of the corresponding acyl-CoA ester.

Acyl Coenzyme A↗
PubMed1997

Glycine 1.0% versus glycine 1.5% as irrigating fluid during transurethral resection of the prostate.

OBJECTIVE: To evaluate the potential benefits of reducing the glycine concentration from 1.5% to 1.0% in the irrigating fluid used during transurethral resection of the prostate (TURP) when 1% ethanol is used as the tracer of absorption. PATIENTS AND METHODS: The effect of 1% ethanol on the tendency for blood to haemolyse was tested in vitro and the optical condition of the irrigating fluids were studied during 10 TURPs. The breath ethanol level was monitored during 423 operations where these fluids were used in a randomized double-blind study. The incidence of 13 symptoms was recorded in the 77 patients who absorbed irrigating fluid. RESULTS: Ethanol slightly lowered the tendency for blood to haemolyse. Reducing the glycine concentration did not alter the optical conditions during TURP. The incidence of symptoms increased significantly as more glycine solution was absorbed, arterial hypotension and nausea being the most usual. Bradycardia, prickling skin sensations and feelings of uneasiness were less common when 1.0% glycine was used, but the choice of irrigating fluid had no effect on the total incidence of symptoms. CONCLUSION: We found no clear advantage in lowering the glycine concentration of the irrigating fluid used during TURP.

Absorption↗
PubMed1981

Interaction of nitrosylruthenium with glycine and alanine in seawater--studies on nitrosylruthenium complex-formations with glycine and alanine by a chelating resin.

RuNO-Chelex 100 resin, [R.RuNO(OH)(OH2)] was prepared by the reaction of RuNO-chloro complex with Chelex 100 resin, and it is expected that aqua and hydroxo groups contained in RuNO-Chelex 100 resin act as adsorption sites for glycinate or alaninate anion by ligand-exchange reaction. The equilibrium constants, Keq, of 1:1 complex formation reactions of RuNO-Chelex 100 resin with glycine and alanine were found to be 96.3 +/- 5.76 and 82.6 +/- 2.69, respectively. The inhibitive effect of glycine and alanine on adsorption of [RuO2(NO2)-(NO3)(H2O)NO]- to anion exchange resin increased in the order of glycine greater than alanine. It was observed that the inhibitive effect was dominated by Keq of RuNO-Chelex 100 resin with glycine and alanine.

Alanine↗
PubMed1988

The glycine-rich region of Escherichia coli D-serine dehydratase. Altered interactions with pyridoxal 5'-phosphate produced by substitution of aspartic acid for glycine.

Replacement of glycine by aspartic acid at either of two sites in a conserved, glycine-rich region inactivates the pyridoxal 5'-phosphate-dependent enzyme D-serine dehydratase (DSD) from Escherichia coli. To investigate why aspartic acid at position 279 or 281 causes a loss of activity, we measured the affinity of the G----D variants for pyridoxal 5'-phosphate and a cofactor:substrate analog complex and compared the UV, CD, and fluorescence properties of wild-type D-serine dehydratase and the inactive variants. The two G----D variants DSD(G279D) and DSD (G281D) displayed marked differences from wild-type D-serine dehydratase and from each other with respect to their affinity for pyridoxal 5'-phosphate and for a pyridoxal 5'-phosphate:glycine Schiff base. Compared to the wild-type enzyme, the cofactor affinity of DSD(G279D) and DSD(G281D) was decreased 225- and 50-fold, respectively, and the ability to retain a cofactor:glycine complex was decreased 765- and 1970-fold. The spectral properties of the inactive variants suggest that they form a Schiff base linkage with pyridoxal 5'-phosphate but do not hold the cofactor in a catalytically competent orientation. Moreover, the amount of cofactor aldamine in equilibrium with cofactor Schiff base is increased in DSD(G279D) and DSD(G281D) relative to that in wild-type DSD. Collectively, our findings indicate that introduction of a carboxymethyl side chain at G-279 or G-281 directly or indirectly disrupts catalytically essential protein-cofactor and protein-substrate interactions and thereby prevents processing of the enzyme bound cofactor:substrate complex. The conserved glycine-rich region is thus either an integral part of the D-serine dehydratase active site or conformationally linked to it.

Algorithms↗
PubMedDate not supplied

Utilization of [1-14C]carbon of glycine of high glycine diet fed young and old rats.

The incorporation of radioactivity from [1-14C]glycine was studied into various organ (serum, liver, muscle) fractions (acid soluble, proteins, lipids, liver glycogen) and carbon dioxide in rats fed with isonitrogenous isocaloric purified diets. The diets contained 30% casein (control), gelatin (exchange of half of the 30% casein) or glycine (corresponding level of glycine in relation to the gelatin diet). The incorporation of radio-activity into proteins was reduced by feeding high glycine diets in young (20-weeks-old) and old (18-month-old) rats in relation to the control diet. The modifications of the results for old animals may be partially explained on the base of a reduced protein turnover rate and adaptation to a high gelatin (glycine) diet.

Aging↗
PubMed2006

Thermal vaporization of biological nanoparticles: fragment-free vacuum ultraviolet photoionization mass spectra of tryptophan, phenylalanine-glycine-glycine, and beta-carotene.

A simple, new way to introduce fragile biomolecules into the gas phase via thermal vaporization of nanoparticles is described. The general utility of this technique for the study of biomolecules is demonstrated by coupling this source to tunable synchrotron vacuum ultraviolet radiation. Fragment-free photoionization mass spectra of tryptophan, phenylalanine-glycine-glycine, and beta-carotene are detected with signal-to-noise ratios exceeding 100. The 8.0 eV photoionization mass spectrum of tryptophan nanoparticles vaporized at 373 K is dominated by a single parent ion peak that exhibits a 20-fold enhancement over the methylene indole fragment ion. The degree of dissociative photoionization of tryptophan can be precisely controlled either by the thermal energy imparted into the neutral tryptophan molecule or by the energy of the ionizing photon. The results reveal how approximately 0.5 eV changes in internal energy affect both the photoionization mass spectrum of tryptophan and the appearance energy of the daughter ion fragments. This method allows the ionization energies of glycine (9.3 +/- 0.1 eV), tryptophan (7.3 +/- 0.2 eV), phenylalanine (8.6 +/- 0.1 eV), phenylalanine-glycine-glycine (9.1 +/- 0.1 eV), and beta-carotene (<7.0 eV) molecules to be determined directly from the photoionization efficiency spectra.

Energy Transfer↗
PubMed1999

Amino acid volume and hydropathy of a transmembrane site determine glycine and anesthetic sensitivity of glycine receptors.

Two specific amino acid residues in transmembrane segments (TM) 2 and 3 are critical for the enhancement of glycine receptor (GlyR) function by volatile anesthetics. To determine which physicochemical characteristics of these sites determine their roles in anesthetic actions, an extensive series of single amino acid mutations at amino acid residue 288 (Ala-288) in TM3 of the alpha1 GlyR subunit was tested for modulation by volatile anesthetics. The mutations changed the apparent affinities of receptors for glycine; replacements with larger volumes and less hydropathy exhibited higher affinities for glycine. Potentiation by anesthetics was reduced by specific mutations at Ala-288. The molecular volume of the substituents was negatively correlated with the extent of potentiation by isoflurane, enflurane, and 1-chloro-1,2,2-trifluorocyclobutane, whereas there was no correlation between anesthetic enhancement and polarity, hydropathy, or hydrophilicity of substituents. In contrast to anesthetics, no correlation was found between the effects of the nonanesthetics 1,2-dichlorohexafluorocyclobutane or 2, 3-dichlorooctafluorobutane and any physicochemical property of the substituent. These results suggest that the molecular volume and hydropathy of the amino acid at position 288 in TM3 regulate glycine and anesthetic sensitivity of the GlyR and that this residue might represent one determinant of an anesthetic binding site.

Alanine↗
PubMed1984

Glycine synthase of the purinolytic bacterium, Clostridium acidiurici. Purification of the glycine-CO2 exchange system.

When the growth medium of Clostridium acidiurici was supplemented with trace metals, glycine synthase and glycine-CO2 exchange activities in cell-free extracts were found to increase significantly. The glycine-CO2 exchange system was purified and shown to consist of a heat-labile component and a heat-stable component. By gel filtration, heat-labile component had an estimated native Mr = 230,000 and contained two subunits of Mr = 65,000 and 58,000 on sodium dodecyl sulfate-polyacrylamide gels, indicating an alpha 2 beta 2 tetramer. Heat-stable component had an estimated Mr = 20,000 and could not be replaced by lipoic acid in reaction mixtures. Pyridoxal phosphate was not bound to either of the purified components but was essential for glycine-CO2 exchange. By spectral analysis, heat-labile component was shown to interact with pyridoxal phosphate and that reductant influenced this interaction.

Amino Acid Oxidoreductases↗
PubMed1990

Glycine, glycyl-glycine and maltodextrin based oral rehydration solution. Assessment of efficacy and safety in comparison to standard ORS.

We evaluated the efficacy and safety of an oral rehydration solution containing glycyl-glycine, glycine, and maltodextrin (GGG-ORS), in comparison to the glucose based ORS (standard ORS). The osmolality of the GGG-ORS (305 mOsm/l) and standard ORS (311 mOsm/l) was similar. Ninety-two children presenting with acute gastroenteritis and moderate dehydration, aged 3 months to 3 years, were randomly assigned to receive standard ORS or GGG-ORS. All the patients were successfully rehydrated orally. The two groups were comparable for baseline characteristics including the microbial etiology. Rotavirus (49%, 36%), ETEC (11%, 18%) or a combination of rotavirus and ETEC (15%, 9%) were the main stool pathogens isolated. There was no significant difference in the mean stool output or duration of diarrhoea between the two groups. Patients in the GGG-ORS group had higher urine output (p less than 0.01) and weight gain (p less than 0.05) in the initial 6 hours when feeding was withheld, but no such differences were observed beyond this period. Hypernatremia did not develop in any patient during the study. We conclude that glycine and glycyl-glycine supplemented oral rehydration solution does not have any therapeutic advantage in the treatment of acute gastroenteritis with moderate dehydration caused predominantly by rotavirus.

Acute Disease↗
PubMed2002

Tyrosine kinases enhance the function of glycine receptors in rat hippocampal neurons and human alpha(1)beta glycine receptors.

Glycine receptors (GlyRs) are transmitter-gated channels that mediate fast inhibitory neurotransmission in the spinal cord and brain. The GlyR beta subunit contains a putative tyrosine phosphorylation site whose functional role has not been determined. To examine if protein tyrosine kinases (PTKs) regulate the function of GlyRs, we analysed whole-cell currents activated by applications of glycine to CA1 hippocampal neurons and spinal neurons. The role of a putative site for tyrosine phosphorylation at position 413 of the beta subunit was examined using site-directed mutagenesis and expression of recombinant (alpha(1)beta(Y413F)) receptors in human embryonic kidney (HEK 293) cells. Lavendustin A, an inhibitor of PTKs, depressed glycine-evoked currents (I(Gly)) in CA1 neurons and spinal neurons by 31 % and 40 %, respectively. In contrast, the intracellular application of the exogenous tyrosine kinase, cSrc, enhanced I(Gly) in CA1 neurons by 56 %. cSrc also accelerated GlyR desensitization and increased the potency of glycine 2-fold (control EC(50) = 143 microM; cSrc EC(50) = 74 microM). Exogenous cSrc, applied intracellularly, upregulated heteromeric alpha(1)beta receptors but not homomeric alpha(1) receptors. Substitution mutation of the tyrosine to phenylalanine at position beta-413 prevented this enhancement. Furthermore, a selective inhibitor of the Src family kinases, PP2, down-regulated wild-type alpha(1)beta but not alpha(1)beta(Y413F) receptors. Together, these findings indicate that GlyR function is upregulated by PTKs and this modulation is dependent on the tyrosine-413 residue of the beta subunit.

Animals↗
PubMed2005

Glycine-amide is an active metabolite of the antiretroviral tripeptide glycyl-prolyl-glycine-amide.

The chemically modified tripeptide glycyl-prolyl-glycine-amide (GPG-NH(2)) inhibits replication of human immunodeficiency virus (HIV) type 1 (HIV-1) in vitro, probably by interfering with capsid formation. The aim of the present study was to determine whether the metabolites glycyl-proline (GP-OH), glycine (G-OH), prolyl-glycine-amide (PG-NH(2)), proline (P-OH), and glycine-amide (G-NH(2)) from proteolytic cleavage may inhibit the replication of HIV-1 in vitro. PG-NH(2) has previously been shown to have a modest effect on HIV-1 replication. In the present study we show that G-NH(2) exhibits a pronounced inhibitory effect on HIV-1. This effect was not due to a decrease in cell proliferation or viability and could not be shown for herpes simplex virus type 1. The G-NH(2) concentration that inhibited virus replication by 50% (IC(50)) was equimolar to that of GPG-NH(2) and ranged from 3 to 41 microM. Transmission electron microscopy revealed that the effect of G-NH(2) on HIV-1 morphology was equivalent to that of GPG-NH(2) and showed disarranged capsid structures, indicating interference with capsid formation. Serial passage of HIV-infected cells with G-NH(2) for more than 20 subcultivations did not decrease the susceptibility to the compound. The results from this study suggest that GPG-NH(2) might act as a prodrug and that G-NH(2) is an active antiretroviral metabolite.

Animals↗
PubMed1982

[Effects of physical loads on the urinary excretion of metabolites from organic solvents. Part I. Change in the urinary excretion of glycine conjugate, hippuric acids, and glycine after a physical burden].

Effects of physical loads on the excretion of urinary glycine conjugates, which are commonly used as an index of organic solvent intake, were examined. After physical exertion by Kendo exercise university students for about 2 hours, urinary protein excretion changed from the levels of (-) or (+) before the exercise to (+) to (formula: see text) after the exercise revealed by the test-tape semi-quantitative indication, and the levels of urinary creatinine increased to approximately 1.9 time and initial level. Under the present experimental conditions, the following results were obtained. 1) Statistically no significant change was observed in the levels of urinary hippuric acid, but an increasing trend was recognized. 2) The glycine levels in the urine decreased and the significance was stressed when the values were adjusted with reference to the specific gravity of urine or to the levels of urinary creatinine. 3) The ratio of hippuric acid to the glycine in the urine increased almost twice as high as the initial ratio and the physical load seemed to promote the glycine conjugation. 4) As to the adjusted levels of urinary metabolites, especially due to several organic solvents, values adjusted with reference to the specific gravity of urine and those to the levels of urinary creatinine correlated well in the samples collected before the exertion. But a poor correlation was observed in the samples collected after the exertion. Therefore, a notice should be given when the adjustment of the values with reference to the levels of urinary creatinine, which is widely used in the health administration practice for organic solvent workers to assess the levels of exposure, since the adjusted values were lowered unnecessarily by excess excretion of creatinine after the physical exertion and the tendency would be exaggerated especially under the low level exposure to organic solvent vapours in the work yard.

Glycine↗
PubMed1990

Mutations that substitute serine for glycine alpha 1-598 and glycine alpha 1-631 in type I procollagen. The effects on thermal unfolding of the triple helix are position-specific and demonstrate that the protein unfolds through a series of cooperative blocks.

Cultured skin fibroblasts from two probands with lethal variants of osteogenesis imperfecta synthesized type I procollagen that was posttranslationally over-modified. Analysis of cDNAs and genomic DNAs from the two probands demonstrated that proband I had a single-base mutation that converted the codon for glycine alpha 1-631 to a codon for serine, and proband II had a single-base mutation that converted the codon for glycine alpha 1-598 to a codon for serine. Although the two serine-for-glycine substitutions were separated by only 35 residues, they had markedly different effects on the thermal unfolding of the collagen triple helix as assayed by brief protease digestion. The type I procollagen from proband I (serine alpha 1-631) had an essentially normal temperature for thermal unfolding. In contrast, type I procollagen from proband II (serine alpha 1-598) was cleaved to readily identifiable intermediate fragments of about 630 residues at 20 degrees C. With procollagens from both probands, collagenase A fragments containing the first 775 amino acids of the alpha chain domains had a lowered temperature for thermal unfolding as assayed by brief protease digestion. The collagenase A fragments from proband I were cleaved to intermediates of about 600 amino acids at 36 degrees C and to fragments of about 510 residues at 37 degrees C. The collagenase A fragments from proband II were cleaved to intermediates of about 630 residues at 32 degrees C, to fragments of about 600 residues at 36 degrees C, and to fragments of about 510 at 37 degrees C. The fragments of about 510 residues from both mutated procollagens were more stable to protease digestion than the collagenase A fragments of 775 residues from normal type I collagen. The results demonstrate that the effects of glycine substitutions on the thermal unfolding of type I collagen are highly position-specific. They also provide direct evidence for previous indications that the triple helix of the protein undergoes micro-unfolding of a series of relatively independent "cooperative blocks" in the predenaturation range of temperatures.

Base Sequence↗
PubMed1995

Localization of glycine neurotransmitter transporter (GLYT2) reveals correlation with the distribution of glycine receptor.

We studied by immunocytochemical localization, the glycine neurotransmitter transporter (GLYT2) in mouse brain, using polyclonal antibodies raised against recombinant N-terminus and loop fusion proteins. Western analysis and immunocytochemistry of mouse brain frozen sections revealed caudal-rostral gradient of GLYT2 distribution with massive accumulation in the spinal cord, brainstem, and less in the cerebellum. Immunoreactivity was detected in processes with varicosities but not cell bodies. A correlation was observed between the pattern we obtained and previously reported strychnine binding studies. The results indicate that GLYT2 is involved in the termination of glycine neurotransmission accompanying the glycine receptor at the classic inhibitory system in the hindbrain.

Amino Acid Transport Systems, Neutral↗
PubMed1997

Choline and glycine betaine uptake in various strains of Rhizobia isolated from nodules of Vicia faba var. major and Cicer arietinum l.: modulation by salt, choline, and glycine betaine.

Two strains of Rhizobia isolated from nodules of Vicia faba var. major and one strain isolated from nodules of Cicer arietinum L. were characterized for salt resistance. The presence of 1 mM glycine betaine or choline in a minimal medium with added NaCl had a beneficial role on the growth of the three strains. Both molecules were found to be taken up by cells obtained at low osmolarity, and whereas glycine betaine uptake activity was stimulated significantly in cells grown in the presence of 0.15 M NaCl, choline uptake activity was strongly inhibited by salt in all tested strains. However, in cells grown with exogenous choline,the uptake inhibition exerted by salt was relieved, mainly in the strain isolated from nodules of C. arietinum L. On the basis of kinetics determinations, in control cells as well as in salt-stressed cells, only high-affinity activities were observed for glycine betaine and choline(apparent Kms between 3 and 18 micro;M). Periplasmic proteins that bound glycine betaine or choline were identified. In nondenaturing conditions, these proteins extracted from the various strains showed different electrophoretic mobility with always a less negative entire charge than the analogous proteins from Rhizobium meliloti.

Betaine↗
PubMed2004

Impaired absorption of marked oligopeptide Glycine-I Tyrosine-Glycine after successful autologous-allotopic ileal mucosa transplantation in beagles.

PURPOSE: After establishing a method for ileal mucosa transplantation in an animal model, the authors investigated the absorptive capacity for oligopeptides of the transplanted mucosa. METHODS: In 14 beagle dogs the authors transplanted ileal mucosa in a vascularized demucosed segment of the transverse colon. The colonic wall-ileal mucosa complex then was integrated in the ileal continuity. Six animals were lost owing to operative complications. Absorptive capacity for oligopeptides was measured in the remaining 8 animals with the iodine 131 (131I)-marked tripeptide glycine-tyrosine-glycine before and 4 weeks after transplantation. The results were compared and analyzed with the Student's t test for matched pairs. Blood concentrations of the marked tripeptide with P value less than .05 were considered as a significant reduction in the absorptive capacity of the transplanted ileal mucosa. After fixation with glutaraldehyd graft, uptake of the colonic wall-ileal mucosa complex was evaluated histologically in 8 animals. RESULTS: In all 8 animals, a 100% graft uptake was verified in all sections. Fifteen minutes after application of 15 MBc Glycine-131I-Tyrosine-Glycine there was no significant difference in the absorption between normal and transplanted ileal mucosa. After 30 minutes, the absorption of the transplanted ileal mucosa showed a tendency (P < .1) for an impaired uptake of the marked tripeptide. However, 60 minutes after application the difference in the absorptive capacity of the transplanted ileal mucosa was significant (P < .05). CONCLUSIONS: Autologous allotopic ileal mucosa transplantation is feasible; however, an impaired absorption of oligopeptides of the transplanted mucosa 4 weeks after transplantation could be observed.

Animals↗
PubMed2004

Immunocytochemical localization of glycine and glycine receptors in the retina of the frog Rana ridibunda.

Glycine and glycine receptors (GlyRs) were analyzed immunocytochemically in the retina of the frog Rana ridibunda. Glycine was localized to somata of glycinergic amacrine and interplexiform cells. Approximately 50% of the cells in the amacrine cell layer were found to be glycinergic. GlyRs of the inner plexiform layer (IPL) were localized to brightly fluorescent puncta, probably representing postsynaptic clusters of GlyRs. GlyR clusters were not evenly distributed across the IPL but showed patterns of stratification specific for the various GlyR subunits. Clusters containing the alpha1 subunit formed four narrow strata within the IPL. Clusters containing the alpha3 subunit were more abundant and covered the whole IPL, with a band of higher density in stratum 3. Clusters of GlyRs were also observed in the outer plexiform layer. Thus, several isoforms of synaptic GlyRs involved with different synapses and inhibitory circuits are present in the frog retina.

Animals↗
PubMed2002

Novel mutations in the P-protein (glycine decarboxylase) gene in patients with glycine encephalopathy (non-ketotic hyperglycinemia).

Eight novel mutations were found in the P-protein (glycine decarboxylase) gene (GLDC) of the glycine cleavage system (EC 2.1.1.10) by screening five exons of the gene in patients with glycine encephalopathy (NKH). The mutations identified were of eight single base changes: a one-base deletion 1054del A, a splice site mutation IVS18-2A-->G and six amino acid substitutions A283P, A313P, P329T, R410K, P700A, and G762R.

Amino Acid Metabolism, Inborn Errors↗