Browse
Submit Data
Databases
API
Help

Dataset Information

8 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

The distinction between gamma-glutamylhydroxamate synthetase and L-glutamine-hydroxylamine glutamyltransferase activities in rat tissues.

ABSTRACT: The formation of gamma-glutamylhydroxamate by homogenates under optimum assay condition showed an inconstancy in the ratios of the enzyme activities utilizing l-glutamate and ATP (gamma-glutamylhydroxamate synthetase) and l-glutamine and ADP (l-glutamine-hydroxylamine glutamyltransferase) in a number of normal and neoplastic rat tissues. Although gamma-glutamylhydroxamate synthetase activities in adult livers and kidneys were identical in males and females, l-glutamine-hydroxylamine glutamyltransferase activities in the organs of females were significantly lower. The developmental formations of the two activities in liver, kidney, brain and muscle were not simultaneous. The l-glutamine-hydroxylamine glutamyltransferase activity in foetal liver or neonatal kidney could be prematurely evoked by thyroxine, but the gamma-glutamylhydroxamate synthetase activity remained unchanged. Injections of cortisol also had dissimilar effects on the two activities in thymus and hepatomas. The discrepant tissue distribution, asynchronous developmental formation and differential response to several hormonal stimuli provide evidence in vivo that the two activities are not catalysed by the same protein.

SUBMITTER: Herzfeld A

PROVIDER: S-EPMC1177670 | biostudies-other | 1973 May

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

The distribution between gamma-glutamylhydrozamate synthetase and L-glutamine-hydroxylamine glutamyltransferase activities in rat tissues. Studies in vitro.

Project description:Two common ways of measuring the potential for glutamine synthesis in a tissue are the rates of formation of gamma-glutamylhydroxamate either by synthesis from glutamate (the glutamylhydroxamate synthetase reaction) or by transfer from glutamine (the glutamyltransferase reaction); it has not been established, however, that either reaction is a specific measure of glutamine synthetase. By differential extraction of glutamylhydroxamate synthetase and glutamyltransferase activities from water homogenates of several rat tissues I obtained an extract, rich in glutamylhydroxamate synthetase activity but nearly devoid of glutamyltransferase activity, and a fraction, solubilized by deoxycholate from the pellet, which contained virtually no glutamylhydroxamate synthetase activity but most of the original glutamyltransferase activity. Synthesis of glutamine, quantitatively similar to the gamma-glutamylhydroxamate formed by glutamylhydroxamate synthetase, is catalysed in the water extract but not in the particulate fraction. gamma-Glutamylhydroxamate formation by glutamylhydroxamate synthetase and glutamyltransferase shows discrepant substrate and metal specificities and can be differentially inhibited by l-methionine sulphoximine, phosphate and adenine nucleotides. The concordance between the formation of glutamine and gamma-glutamylhydroxamate by glutamylhydroxamate synthetase but not by glutamyltransferase and the different solubilities of the glutamylhydroxamate synthetase and glutamyltransferase enzyme activities demonstrate that these two activities are not inextricably associated; they therefore cannot be catalysed exclusively by the same protein.

| S-EPMC1177669 | biostudies-other

Highly Elevated Plasma γ-Glutamyltransferase Elevations: A Trait Caused by γ-Glutamyltransferase 1 Transmembrane Mutations.

Project description: Not available

| S-EPMC7155009 | biostudies-literature

A radiochemical assay for glutamine synthetase, and activity of the enzyme in rat tissues.

Project description:1. A radiochemical assay for glutamine synthetase has been developed in which an ATP-regenerating system is incorporated to prevent accumulation of inhibitory amounts of ADP. It is particularly suitable for assay of the enzyme in crude tissue extracts containing high adenosine triphosphatase activity. 2. A survey of the distribution of the enzyme in tissues from normal male rats showed that activity is present in liver, brain cortex, kidney cortex, spleen, testis and retina. 3. The K(m) of the enzyme for l-glutamate is approx. 1.5x10(-2)m.

| S-EPMC1179075 | biostudies-other

Multi-omics Biomarker Pipeline Reveals Elevated Levels of Protein-glutamine Gamma-glutamyltransferase 4 in Seminal Plasma of Prostate Cancer Patients.

Project description:Seminal plasma, because of its proximity to prostate, is a promising fluid for biomarker discovery and noninvasive diagnostics. In this study, we investigated if seminal plasma proteins could increase diagnostic specificity of detecting primary prostate cancer and discriminate between high- and low-grade cancers. To select 147 most promising biomarker candidates, we combined proteins identified through five independent experimental or data mining approaches: tissue transcriptomics, seminal plasma proteomics, cell line secretomics, tissue specificity, and androgen regulation. A rigorous biomarker development pipeline based on selected reaction monitoring assays was designed to evaluate the most promising candidates. As a result, we qualified 76, and verified 19 proteins in seminal plasma of 67 negative biopsy and 152 prostate cancer patients. Verification revealed a prostate-specific, secreted and androgen-regulated protein-glutamine gamma-glutamyltransferase 4 (TGM4), which predicted prostate cancer on biopsy and outperformed age and serum Prostate-Specific Antigen (PSA). A machine-learning approach for data analysis provided improved multi-marker combinations for diagnosis and prognosis. In the independent verification set measured by an in-house immunoassay, TGM4 protein was upregulated 3.7-fold (p = 0.006) and revealed AUC = 0.66 for detecting prostate cancer on biopsy for patients with serum PSA ?4 ng/ml and age ?50. Very low levels of TGM4 (120 pg/ml) were detected in blood serum. Collectively, our study demonstrated rigorous evaluation of one of the remaining and not well-explored prostate-specific proteins within the medium-abundance proteome of seminal plasma. Performance of TGM4 warrants its further investigation within the distinct genomic subtypes and evaluation for the inclusion into emerging multi-biomarker panels.

| S-EPMC6731075 | biostudies-literature

Genetically elevated gamma-glutamyltransferase and Alzheimer's disease.

Project description:Observational epidemiological evidence supports a linear and independent association between serum gamma-glutamyltransferase (GGT) concentrations and the risk of Alzheimer's disease (AD). However, the causality of this association has not been previously investigated. We sought to assess the causal nature of this association using a Mendelian randomization (MR) approach. Using inverse-variance weighted MR analysis, we assessed the association between GGT and AD using summary statistics for single nucleotide polymorphism (SNP)-AD associations obtained from the International Genomics of Alzheimer's Project of 17,008 individuals with AD and 37,154 controls. We used 26 SNPs significantly associated with GGT in a previous genome-wide association study on liver enzymes as instruments. Sensitivity analyses to account for potential genetic pleiotropy included MR-Egger and weighted median MR. The odds ratio of AD was 1.09 (95% confidence interval, 0.98 to 1.22; p = 0.10) per one standard deviation genetically elevated GGT based on all 26 SNPs. The results were similar in both MR-Egger and weighted median MR methods. Overall, our findings cannot confirm a strong causal effect of GGT on AD risk. Further MR investigations using individual-level data are warranted to confirm or rule out causality.

| S-EPMC5915296 | biostudies-literature

Glutamine synthetase regulates the alternative metabolism of γ-aminobutyrate in oral squamous cell carcinoma

Project description:More than 90% of cancer cases in head and neck region are oral squamous cell carcinoma. Recent studies identified several tumor-specific metabolites for the screening or diagnosis of OSCC patients. However, the metabolic reprogramming of OSCC is not well understood. Here, we compared the metabolites between cancerous and paracancerous tissues of OSCC patients and investigated the metabolism of γ-aminobutyrate in OSCC derived cells. Our data revealed that the increase of γ-aminobutyrate was promoted by the synthesis of glutamate beyond the mitochondria, which was regulated by glutamine synthetase. This study is not only benefit for understanding the pathological mechanisms of OSCC, but also has application prospects for the diagnosis and therapy of OSCC.

2023-07-06 | GSE222879 | GEO

Cytosolic glutamine synthetase 1;1 knockout effects on rice roots

Project description:Goal of the study is to characterize distinct function(s) of two cytosolic glutamine synthetase (GS) in rice plants. We grew rice lacking GS1;1 and GS1;2 under the ammonium sufficient condition. We harvested roots from the two mutants as well as those of the corresponding control.

2019-04-01 | E-MTAB-6303 | biostudies-arrayexpress

Oxidized LDL, Gamma-Glutamyltransferase and Adverse Outcomes in Older Adults.

Project description:OBJECTIVES:Gamma-glutamyltransferase (GGT) is a biomarker of liver disease and oxidative stress which was associated with all-cause and cardiovascular (CV) mortality in the general population and in patients with high risk conditions. This study aims at assessing whether oxLDL modifies the relationship between GGT, all-cause, and CV mortality in elderly individuals from the general population. DESIGN:Observational longitudinal study. SETTING:Population-based cohort of older individuals (>65 years) free of liver disease. PARTICIPANTS:One thousand and thirty-eight individuals from the Invecchiare in Chianti (InCHIANTI) study. MEASUREMENTS:Serum GGT level, oxidized low-density lipoprotein (oxLDL), CV comorbidities, all-cause and CV mortality. RESULTS:The median age of the study population (n = 1,038) was 74 years (inter-quartile range: 69-79), 152 individuals (15%) had past CV events. During a median follow-up of 9 years, 401 individuals died, 168 of them (42%) for CV causes. In adjusted analyses, GGT predicted all-cause mortality (HR for 20 U/L increase in serum GGT: 1.11, 95% CI: 1.02-1.21, P = .02) and CV mortality (HR: 1.17, 95% CI: 1.03-1.33; P = .02). Furthermore, in an analysis for interaction circulating oxLDL amplified the effect of GGT on all-cause mortality (P = .003). CONCLUSION:Circulating oxLDL amplifies the effect of GGT on mortality in the elderly. The mechanism for this association remains unknown and requires further research, including studying the potential role of GGT in oxidative stress. These results are consistent with the hypothesis of a causal role of GGT in the CV morbidity and mortality in older individuals and indicate that oxLDL plays a crucial role in the interpretation of the link between GGT and the risk of adverse clinical events in this population.

| S-EPMC5407291 | biostudies-literature

Serum Gamma-Glutamyltransferase Levels Predict Clinical Outcomes in Hemodialysis Patients.

Project description:BackgroundGamma-glutamyltransferase (GGT) is a biomarker of liver injury. GGT has also been reported to be a marker of oxidative stress and a predictor of mortality in the general population. Hemodialysis (HD) patients suffer from oxidative stress. The aim of our study was to investigate the relationship between serum GGT levels and clinical outcomes in HD patients.MethodsA total of 1,634 HD patients were enrolled from the Clinical Research Center registry for end-stage renal disease, a prospective cohort in Korea. Patients were categorized into three groups by tertiles of serum GGT levels. The primary outcome was all-cause, cardiovascular, or infection-related mortality and hospitalization.ResultsDuring the median follow-up period of 30 months, the highest tertile of serum GGT levels had a significantly higher risk for all-cause mortality (hazard ratio (HR) 2.39, 95% confidence interval (CI), 1.55-3.69, P<0.001), cardiovascular mortality (HR 2.14, 95% CI, 1.07-4.26, P = 0.031) and infection-related mortality (HR 3.07, 95% CI, 1.30-7.25, P = 0.011) using tertile 1 as the reference group after adjusting for clinical variables including liver diseases. The highest tertile also had a significantly higher risk for first hospitalization (HR 1.22, 95% CI, 1.00-1.48, P = 0.048) and cardiovascular hospitalization (HR 1.42, 95% CI, 1.06-1.92, P = 0.028).ConclusionsOur data demonstrate that high serum GGT levels were an independent risk factor for all-cause, cardiovascular, and infection-related mortality, as well as cardiovascular hospitalization in HD patients. These findings suggest that serum GGT levels might be a useful biomarker to predict clinical outcomes in HD patients.

| S-EPMC4573328 | biostudies-literature

Gamma-glutamyltransferase as novel biomarker in patients with uterine leiomyosarcoma.

Project description:Gamma-glutamyltransferase (GGT) is an established marker for proliferative/apoptotic balance and has been associated with cancer risk and prognosis. The aim of this study was to evaluate the value of pre-treatment GGT serum levels as prognostic biomarker in patients with primary uterine leiomyosarcoma (ULMS). Data of women with ULMS were extracted from a multi-center database. Pre-treatment GGT serum levels were measured and patients assigned to predefined GGT risk groups. GGT values were correlated with clinico-pathological parameters and univariate and multivariable survival analyses were performed. A total of 44 patients with ULMS were analyzed. Mean (SD) pre-therapeutic GGT serum level was 33.8 (39.8) U/L. In Figo Stage I versus II-IV mean (SD) GGT values were 28.8 (34.0) U/l and 43.5 (49.2) U/l, respectively (p?=?0.25). Five-year overall survival (OS) rates in ULMS patients with normal low versus higher GGT levels were 70% and 37%, respectively (p?=?0.043). Univariate and multivariable analyses revealed that higher GGT serum levels (p?=?0.043, p?=?0.005) and high histological grade (p?=?0.029, p?=?0.012) were independently associated with impaired OS, respectively. Higher pre-treatment GGT serum levels were independently associated with unfavorable prognosis in women with ULMS. Thus, GGT seems to be a useful novel biomarker in ULMS.

| S-EPMC5028736 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data