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Corynebacterium glutamicum AJ1511 and Escherichia coli BW25113 strains were compared in terms of resistance to sarcosine (N-methylglycine). The E. coli strain was more sensitive to sarcosine than C. glutamicum, especially when grown in minimal medium. Growth inhibition of the BW25113 strain in minimal M9 medium containing 0.5 m sarcosine was overcome by the addition of glycine. Inactivation of the glycine cleavage (GCV) system (gcvP) as well as the removal of its activator (gcvA) in BW25113 cells increased the threshold for sarcosine inhibition up to 0.75 m. Activation of the promoter of the E. coli gcvTHP operon by 0.1-0.4 m sarcosine added to M9 medium was demonstrated in vivo using dasherGFP as the reporter. Sensitivity to sarcosine on glucose minimal medium is suggested to be a characteristic of Gram-negative bacteria with GcvA/GcvR regulation of the GCV system. [ABSTRACT FROM AUTHOR]

Accurate determination of Sarcosine (SAR) in urine with high sensitivity and selectivity is important, because it was recently recommended as a prospective biomarker for prostate cancer (PCa) and significant for the early identification of PCa. In this study, an electrochemical sensor based on Fe 3 O 4 incorporated metal–organic frameworks (MOFs) @molecularly imprinted polymer (MIP) was constructed for SAR detection. Magnetic Fe 3 O 4 nanoparticles embedded zeolitic imidazolate framework-8 (ZIF-8) was used as the support of MIP. MIP provides specific recognition sites for template molecules SAR and MOFs increase the rate of mass transfer and adsorption capacity due to the porous structure. The synthesized super-magnetic Fe 3 O 4 @ZIF-8@MIP was self-assembled onto an Au electrode in magnetic field and used as the sensing unit of electrochemical sensor. Cyclic voltammetry was used to monitor the electrochemical behavior, and the binding of SAR resulted in a reduction in the measured current. The results revealed a wide linear range from 1 to 100 pM towards trace SAR determination, with extremely low limit of detection down to 0.4 pM. In conclusion, the Fe 3 O 4 @ZIF-8@MIP based sensor provides a selective, sensitive, and convenient method for SAR diagnosis and other cancer marker detection. [ABSTRACT FROM AUTHOR]

DNA hypermethylation is one of the most common epigenetic modifications in prostate cancer (PCa). Several studies have delineated sarcosine as a PCa oncometabolite that increases the migration of malignant prostate cells while decreasing their doubling time. Here, we show that incubation of prostate cells with sarcosine elicited the upregulation of sarcosine N‐demethylation enzymes, sarcosine dehydrogenase and pipecolic acid oxidase. This process was accompanied by a considerable increase in the production of the major methyl‐donor S‐adenosylmethionine (SAMe), together with an elevation of cellular methylation potential. Global DNA methylation analyses revealed increases in methylated CpG islands in distinct prostate cell lines incubated with sarcosine, but not in cells of nonprostate origin. This phenomenon was further associated with marked upregulation of DNA methyltransferases (Dnmts). Epigenetic changes were recapitulated through blunting of Dnmts using the hypomethylating agent 5‐azacytidine, which was able to inhibit sarcosine‐induced migration of prostate cells. Moreover, spatial mapping revealed concomitant increases in sarcosine, SAMe and Dnmt1 in histologically confirmed malignant prostate tissue, but not in adjacent or nonmalignant tissue, which is in line with the obtained in vitro data. In summary, we show here for the first time that sarcosine acts as an epigenetic modifier of prostate cells and that this may contribute to its oncometabolic role. [ABSTRACT FROM AUTHOR]

The aim of the investigation was to test whether genetic variants predicted to impair the functionality of SLC6A9 , which codes for the GlyT-1 glycine transporter, are protective against schizophrenia. In an exome sequenced sample of 4225 schizophrenia cases and 5834 controls, variants occurring in SLC6A9 were annotated and weights were assigned using GENEVARASSOC. Genotype counts were compared using SCOREASSOC. Variants predicted to be deleterious by SIFT and damaging by PolyPhen were examined. Genotypes at 1:44466494-G/A seemed likely to be erroneous. If these were ignored then there were 15 damaging variants in controls and five in cases. The results are consistent with the hypothesis that variants which damage SLC6A9 are protective against schizophrenia but a larger sample would be required to confirm this. [ABSTRACT FROM AUTHOR]

Amino acids are emerging as alternative solvents for absorption-based CO 2 capture, but their potential to form the harmful byproducts nitrosamines is not well understood. This study investigated the formation of nitrosamines from model amino acids sarcosine, proline, and taurine under desorber- and absorber-relevant conditions. Special attention was paid to the effects of base and the formation of volatile nitrosamines. Under simulated desorber conditions, all three amino acid solvents with organic base monoethanolamine (MEA) formed more total nitrosamines than those with inorganic base sodium hydroxide (NaOH). Increasing base concentration decreased the formation of N -nitrososarcosine (NSAR) in both NaOH- and MEA-based sarcosine solvents. By measuring NSAR formation under varying base concentration and CO 2 loading, it was shown that both sarcosine carbamic acid (SARCOOH) and deprotonated sarcosine (SAR − ) contributed to NSAR formation. Volatile nitrosamine N -nitrosodimethylamine (NDMA) was detected in sarcosine solvents at levels three orders of magnitude lower than NSAR. Kinetic modeling showed that 61%–110% of the accumulated NDMA was formed through NSAR decomposition. NDMA formation from NSAR was promoted by increasing MEA concentration, but suppressed by increasing NaOH concentration. Under simulated absorber conditions, NaOH- and MEA-based solvents formed total nitrosamines at similar rates for sarcosine, proline, and taurine. In sarcosine solvents, NDMA formed at levels three orders of magnitude lower than NSAR, similar to that under desorber conditions. [ABSTRACT FROM AUTHOR]

The use of amino acids as potential solvents for carbon dioxide (CO 2 ) capture has been considered by a number of researchers. However, very little is known about the kinetics and mechanism of amino acids-CO 2 reactions. In this work, we investigate the reactions of three amino acids ( l -Arginine, Glycine and Sarcosine) with CO 2 in aqueous media using stopped-flow conductivity technique. The experiments were performed at temperatures between 293 and 313 K and amino acids concentrations were in the range of 0.05–0.2 molar. The overall rate constants (k ov ) was found to increase with increased amino acid concentration and solution temperature. Both zwitterion and termolecular mechanisms were used to model and interpret the data. However, the Zwitterion mechanism was found to be the preferred one. From the stopped-flow results at pH around 6, we found that neutral l -Arginine, Glycine and Sarcosine react with CO 2 (aq) with k (M −1 s −1 ) = 2.81 × 10 10 exp( − 4482.9 T ( K ) ), k (M −1 s −1 ) = 3.29 × 10 13 exp( − 8143.7 T ( K ) ) and k (M −1 s −1 ) = 3.90 × 10 13 exp( − 7991.0 T ( K ) ) respectively. The corresponding activation energies are 37.28 kJ mol −1 , 67.71 kJ mol −1 And 66.44 kJ mol −1 respectively. A comparison between the kinetics of the three amino acids showed that Arginine exhibits highest reaction rate with CO 2 followed by Sarcosine and then Glycine. The technique and results obtained from this work can be used as strong tools in the development of efficient new solvents for the removal of CO 2 from flue and industrial gases. [ABSTRACT FROM AUTHOR]

Objectives: Regular aerobic exercise provides beneficial effects on human health and reduces all-cause mortality. Aerobic exercise has profound metabolic effects, and specific metabolites may reflect physiological changes. We aimed to identify endogenous metabolites that distinguish the trained from the untrained state to increase the spectrum of analytes amenable for hypothesis testing and to expand understanding of putative beneficial pathways.Design: Cross sectional laboratory repeated measures study.Methods: Exercise testing was performed in 37 healthy male participants and serum samples were obtained before and after completion of a ten-week standardized exercise program. Samples were analyzed for routine clinical parameters and for 188 endogenous metabolites by LC-MS/MS.Results: Indicating the effectiveness of the intervention program, parameters of sport physiology were different after training. After correcting for multiple testing, serum concentrations of several metabolites differed between the trained and untrained state. Serine and glutamate decreased in response to exercise, whereas sarcosine and kynurenine increased. Phosphatidylcholines showed a mixed response in that four species increased and three decreased. However, all seven lysophosphatidylcholines and all four plasmalogens that differed between the trained and untrained state, increased. One short-chain acylcarnitine also decreased. In receiver operator characteristics analyses, sarcosine displayed the highest AUC value (0.839; 95% CI: 0.734-0.926) in discriminating the pre- from the post-trained state.Conclusions: Our study detected metabolites that clearly differentiate the trained from the untrained state. These metabolites may be targeted in mechanistic studies to understand underlying biochemical pathways and could serve to improve the design, monitoring and individualization of training programs. [ABSTRACT FROM AUTHOR]

Purpose: The aims of this study were to compare the expression of sarcosine metabolism- related proteins between invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) and to determine the implications of these results. Materials and Methods: Tissue microarrays were constructed, containing 30 samples from normal breast tissue, 114 samples from patients with ILC, and 692 samples from patients with IDC. Immunohistochemical staining was performed to examine the expression of sarcosine metabolism-related proteins [glycine N-methyltransferase, sarcosine dehydrogenase, and l-pipecolic acid oxidase (PIPOX)]. Results: The sarcosine metabolic phenotype differed between ILC and IDC (p<0.001). In IDC, sarcosine metabolic phenotype was distributed as null type (61.7%)>low sarcosine type (30.4%)>high sarcosine type (5.0%)>intermediate type (2.9%). However, in ILC, the sarcosine metabolic phenotype was distributed as low sarcosine type (61.4%)>null type (32.5%)>intermediate type (5.3%)>high sarcosine type (0.9%). PIPOX showed higher expression in ILC than in IDC (p<0.001) and correlated with androgen receptor (AR) positivity (p=0.001) in ILC. Conclusion: Expression of sarcosine metabolism-related proteins differed between ILC and IDC. Low sarcosine type was the majority sarcosine metabolic phenotype of ILC. PIPOX expression was predominant in ILC and correlated with AR positivity. [ABSTRACT FROM AUTHOR]

Highlights: [•] Glycine, sarcosine and proline improve the absorption of CO2 into a K2CO3 solvent. [•] Reaction kinetics between CO2 and the aforementioned amino acids are reported. [•] Glycine and MEA exhibit a comparable catalytic activity. [•] Sarcosine and proline possess a larger catalytic activity than that of DEA. [ABSTRACT FROM AUTHOR]

Abstract: Qualitative 13C-NMR experiments were performed at 298 K and for different loadings to investigate the liquid speciation in amino acid neutralized by both strong inorganic and weak organic bases. The two different systems, potassiumsarcosinate(KSAR) and sarcosine blended with equinormal quantities of 3-(methylamino)propylamine (MAPA-SAR) were studied. In presence of CO2, the spectra of the MAPA-SAR system showed more species than that of the K-SAR system due to the presence of carbamates from the primary, secondary and amino acid amine groups even at very low loadings. This means that complete neutralization of sarcosine with MAPA does not occur since carbamates of the primary and secondary amine group of MAPA were formed in the system. In order to quantify the percentage of carbamate formed on the amine group of sarcosine compared to carbamates formed on MAPA, a quantitative 13C-NMR experiment is needed as a future work. [Copyright &y& Elsevier]

Purpose: Sarcosine in prostate cancer tissue samples was recently reported to be increased during prostate cancer progression to metastasis and suggested to be a key metabolite of cancer cell invasion and aggressiveness. We reevaluated sarcosine in prostate cancer tissue samples as a potential indicator of tumor aggressiveness, and as a predictor of recurrence-free survival. Materials and Methods: Sarcosine in matched samples of malignant and nonmalignant tissue from 92 patients with prostate cancer after radical prostatectomy was measured in the framework of a global metabolite profiling study of prostate cancer by gas chromatography/mass spectrometry. We related results to age, prostate volume, tumor stage, Gleason score, preoperative prostate specific antigen and biochemical recurrence, defined as a persistent prostate specific antigen increase of greater than 0.2 ng/ml. Nonparametric statistical tests, ROC curves and Kaplan-Meier analyses were done. Results: Median sarcosine content in tissue was about 7% higher in matched malignant vs nonmalignant samples, which was significantly. Sarcosine values were not associated with tumor stage (pT2 vs pT3), tumor grade (Gleason score less than 7 vs 7 or greater) or biochemical recurrence. The lack of metastatic tissue samples was a study limitation. Conclusions: Sarcosine in prostate cancer tissue samples cannot be considered a suitable predictor of tumor aggressiveness or biochemical recurrence. [ABSTRACT FROM AUTHOR]