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Aim: To quantify the association between serum sarcosine and diabetic retinopathy (DR) using weighted gene co‐expression network analysis (WGCNA). Methods: We measured serum metabolites in 69 pairs of type 2 diabetes (T2D) patients with and without DR matched by age, gender, body mass index（BMI and HbA1c, using a propensity score matching‐based approach. To identify modules and metabolites linked to DR, pathway analysis was performed using WGCNA, the Kyoto Encyclopedia of Genes and Genomes and Small‐Molecule Pathway Database. The association of sarcosine with DR was estimated by restricted cubic spline and conditional logistic regression models. Its joint effects with covariates on DR were also extensively examined. Results: With per interquartile range elevation of sarcosine, the adjusted odds ratio (AOR) of DR significantly decreased by 67% (AOR: 0.33, 95% confidence interval [CI]: 0.19‐0.58). Similar results were also found in the tertile analysis. Compared with those in the first tertile of sarcosine, the AOR significantly decreased by 54% (AOR: 0.46, 95% CI: 0.18‐1.17) and 78% (AOR: 0.22, 95% CI: 0.08‐0.59) for subjects in the second and third tertiles, respectively. Compared with subjects with lower sarcosine and lower HDL‐C levels, those with higher sarcosine and lower HDL‐C levels had the lowest odds of DR (OR: 0.13, 95% CI: 0.04, 0.43). Conclusions: Serum sarcosine was inversely related to DR, especially in T2D patients with insufficient HDL‐C. This study provides insights on a possible novel target for DR precision prevention and control, as well as a better understanding of the DR mechanism. [ABSTRACT FROM AUTHOR]

Conventional luminol chemiluminescence (CL) is widely used in imaging and analytical assays. As far as we can search, there are no studies on the use of CL for information encryption and protection. Here, a novel CL hydrogel is developed. A rapid color visualization of sarcosine in urine using a mobile phone camera is achieved based on CL energy resonance transfer. Four different colors of CL hydrogels are prepared by adding different ratios of rhodamine B or fluorescein. In the multicolor CL hydrogels, activated CL can generate conventional multicolor code shift and original white light. The luminescence duration and the cause of the white light are analyzed using CL spectroscopy. Sarcosine oxidase is replaced with sarcosine in the multicolor CL hydrogels to obtain the translation of editable code, which facilitates the secondary information encryption and code transmissions. The effective luminescence time of these hydrogels are short (13–50 min), and code can be deleted naturally. [ABSTRACT FROM AUTHOR]

A new fluorescent probe based on Eu (III) incorporated BSA‐AuNCs is developed for the selective sensing of sarcosine. Sarcosine is a simple non‐proteinogenic amino acid which is a clinical biomarker for prostate cancer. The non‐invasive sensing of a metabolite biomarker sarcosine for prostate cancer from urine sample was achieved through the developed Eu (III) incorporated BSA‐AuNCs probe. The developed sensor exhibited a good sensitivity and selectivity towards the metabolite sarcosine and observed no significant interference with other coexisting metabolites present in urine. The probe shows a very lower Limit of detection (LOD) of 0.177 mM and this probe can be developed for determining sarcosine on clinical basis. Considering its predominance and the pain associated invasive prostate cancer clinical examinations for the diagnosis, a non‐invasive diagnosis is of great need and significance. [ABSTRACT FROM AUTHOR]

Sphingomonas paucimobilis' P450SPα (CYP152B1) is a good candidate as industrial biocatalyst. This enzyme is able to use hydrogen peroxide as unique cofactor to catalyze the fatty acids conversion to α‐hydroxy fatty acids, thus avoiding the use of expensive electron‐donor(s) and redox partner(s). Nevertheless, the toxicity of exogenous H2O2 toward proteins and cells often results in the failure of the reaction scale‐up when it is directly added as co‐substrate. In order to bypass this problem, we designed a H2O2 self‐producing enzyme by fusing the P450SPα to the monomeric sarcosine oxidase (MSOX), as H2O2 donor system, in a unique polypeptide chain, obtaining the P450SPα‐polyG‐MSOX fusion protein. The purified P450SPα‐polyG‐MSOX protein displayed high purity (A417/A280 = 0.6) and H2O2‐tolerance (kdecay = 0.0021 ± 0.000055 min−1; ΔA417 = 0.018 ± 0.001) as well as good thermal stability (Tm: 59.3 ± 0.3°C and 63.2 ± 0.02°C for P450SPα and MSOX domains, respectively). The data show how the catalytic interplay between the two domains can be finely regulated by using 500 mM sarcosine as sacrificial substrate to generate H2O2. Indeed, the fusion protein resulted in a high conversion yield toward fat waste biomass‐representative fatty acids, that is, lauric acid (TON = 6,800 compared to the isolated P450SPα TON = 2,307); myristic acid (TON = 6,750); and palmitic acid (TON = 1,962). [ABSTRACT FROM AUTHOR]

Sarcosine level in serum is of important clinical significance in distinguishing prostate cancer. This work depicts an amperometric sarcosine biosensor with good anti-interference performance by electro-codepositing manganese phosphate, 3,4-ethylenedioxythiophene (EDOT) and indole-6-carboxylic acid (IA) on the glass carbon electrode. The prepared sarcosine biosensor has a wide linear detection range (1-55 µM) with a low detection limit of 0.11 µM. This work provides an antiinterference approach by controlling the surface charge density of the biosensor to sarcosine sensing, which has great potential to be used as point of care testing (POCT) device for the rapid detection of prostate cancer biomarkers. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides (AMPs) are potential therapeutic agents against bacteria. We recently showed that a rationally designed AMP, termed Stripe, with an amphipathic distribution of native cationic and hydrophobic amino acids on its helical structure exhibited potent antimicrobial activity against Gram‐positive and Gram‐negative bacteria with negligible hemolytic activity and cytotoxicity. In this study, the structure–activity relationship of Stripe was elucidated by designing a series of antimicrobial peptides whereby amino acid residues of Stripe were exchanged with helix‐destabilizing sarcosine residues. Stripe 1–5 peptides with hydrophobic amino acids substituted with sarcosine were predominantly unstructured and showed no antimicrobial activity, except against Escherichia coli (E. coli) (DH5α) cells. The activity against E. coli (DH5α) cells and the helicity of Stripe 1–5 peptides decreased concomitantly as the number of sarcosine residue substitutions increased. Stripe 1–5 peptides showed no hemolytic activity or cytotoxicity. The results indicate that sarcosine substitutions provide an approach to study the structure–activity relationship of helical AMPs, and the helicity of Stripe is an important feature defining its activity. [ABSTRACT FROM AUTHOR]

Objective: Modulation of glutamatergic neurotransmission in schizophrenia by sarcosine leads to a reduction in primary negative symptoms, while its metabolic profile is safe. In order to extend research in the area, we assessed serum levels of neuropeptide Y (NPY), a hypothalamic hormone related to anxiety and depression, also involved in mechanisms inducing weight gain. Additionally, we analyzed associations between NPY concentrations and its changes with severity of symptoms and metabolic parameters. Methods: A prospective 6‐month, randomized, double‐blind placebo‐controlled trial was completed by 57 subjects with chronic schizophrenia with predominant negative symptoms and stable antipsychotic treatment. The participants received 2 g of sarcosine (n = 28) or placebo (n = 29) daily. We assessed serum NPY concentrations and severity of symptoms (with the Positive and Negative Syndrome Scale [PANSS] and Calgary Depression Scale for Schizophrenia) at the beginning of the study, after 6 weeks and 6 months. Results: Sarcosine did not affect NPY levels in all time points. The highest decrease in NPY concentrations was observed in the subjects who were initially depressed, who became euthymic at the last visit. We noticed an improvement in the total PANSS score, and negative symptom and general psychopathology subscales in the sarcosine group, however, without any correlation with NPY levels. Conclusion: The use of sarcosine does not change NPY levels. Peripheral NPY concentrations may be related to depressive symptoms in schizophrenia. [ABSTRACT FROM AUTHOR]

Employment of metal nanoparticles has been one of the most promising synthetic strategies for a number of chemical transformations. New spiroindane‐1,3‐diones were synthesized through [3 + 2] cycloaddition in moderate to high yields by a three‐component reaction of heterocyclic chalcone derivatives, ninhydrin, and sarcosine/L‐proline. The presence of heterogenous MgSiO3 nanoparticles (NPs) under microwave irradiation showed a robust effect in improving the yield of the desired products. Furthermore, the catalyst may be recovered and reused without significant loss of activity. [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]

To date, there has been no evidence regarding the association between urinary sarcosine content and prostate cancer survival. Our main objective was to investigate whether levels of post‐treatment urinary sarcosine are associated with relapse. The inclusion criteria were (in accordance with EAU 2017) as follows: histopathologically verified adenocarcinoma in prostate biopsy cores or specimens from transurethral resection of the prostate (TURP) or prostatectomy for benign prostatic enlargement (BPE) with retained ability to urinate. The median follow‐up was 53 months. In the study, we retrospectively evaluated a cohort of 511 patients with prostate cancer with various risk factors and treatment strategies. Post‐treatment sarcosine levels were elevated in 266 (52%) patients and highly elevated (≥200 nmol/L) in 71 (13%) patients. Urinary sarcosine content was significantly associated with number of relapses that patients experienced, P = 0.002 for sarcosine ≥200 vs ≤30 nmol/L. Multivariate analysis revealed that sarcosine was an independent predictor of recurrent relapses (≥2 relapses with an intermediate period of remission), HR = 3.89 (95% CI 1.29‐11.7) for sarcosine >200 vs <30 nmol/L. This trend was even more pronounced in a subgroup of patients who underwent radical prostatectomy, HR = 3.29 (95% CI 1.06‐10.18), where (single) relapse‐free survival could also be predicted by sarcosine levels, HR = 1.96 (1.05‐3.66). Urinary sarcosine may become a possible predictor for patients' outcomes, because patients with elevated post‐treatment sarcosine could be predicted to have recurrent relapses of the disease. Risk of relapses is increased in prostate cancer patients with high post‐treatment urinary sarcosine, as shown by a retrospective study on 511 patients. [ABSTRACT FROM AUTHOR]

Abstract: Sarcosine is a potential prostate cancer marker. In this study, we developed a method of three‐phase solvent bar liquid‐phase microextraction combined with high‐performance liquid chromatography to determine sarcosine after derivatization with 4‐dimethylarminoazobenzene‐4‐sulfonyl chloride from human urine. The effects of different extraction conditions on extraction efficiency were investigated and optimized. Under optimum experimental conditions, a calibration graph exhibited linearity over the range of 0.05–25 μmol/L with a correlation coefficient (r2) of 0.9990. The enrichment factor was 168, and the detection limit was 0.02 μmol/L. The method was successfully used to analyze sarcosine in human urine and non‐invasive detection, and good spiked recoveries ranging from 90.5 to 93.6% were obtained. The proposed method exhibited high sensitivity, high enrichment factor, good precision, and a simple setup. It may contribute to the early accurate diagnosis and the progression monitoring of prostatic carcinoma. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Augmentation of sarcosine, a natural inhibitor of the glycine transporter type I, normalizes glutamatergic neurotransmission, having beneficial impact on primary negative symptoms in schizophrenia and may also influence immune system and interleukin 6 (IL‐6) levels. Aim: Finding a relationship between initial IL‐6 serum concentrations or its changes and severity of symptoms as a result of sarcosine addition to stable antipsychotic treatment. Method: Fifity‐eight individuals with schizophrenia with predominantly negative symptoms completed a 6‐month randomized, double‐blind placebo‐controlled prospective study. Patients received 2 g of sarcosine (n = 29) or placebo (n = 30) daily per os. We measured IL‐6 levels and severity of symptoms at the beginning, after 6 weeks and 6 months. As main clinical tools, we used Positive and Negative Syndrome Scale (PANSS) and Calgary depression scale for schizophrenia (CDSS). Results: Augmentation with sarcosine had no effect on IL‐6 serum levels in all time points. We noted significant improvements in negative symptoms, general psychopathology, and total PANSS score in the sarcosine group. We found correlation of initial serum IL‐6 with severity of positive symptoms and negative association between IL‐6 levels reduction and positive symptoms reduction. Conclusions: Sarcosine does not significantly affect IL‐6 concentrations but IL‐6 may be involved in mechanisms related to the presence of positive symptoms. [ABSTRACT FROM AUTHOR]

Abstract: Microsolvation of neutral and zwitterionic conformations of sarcosine is explored at ωB97XD/6‐311++G(d,p) level. Natural Bond Orbital and Boltzman population results are used to show the importance of the methyl group in sarcosine. Various configurations have been considered to locate the low lying configuration of sarcosine (neutral and zwitterionic forms) with one to four water molecules. The various sarcosine‐(water)1‐4 clusters have been analyzed with the established hydrogen bonding networks. The current findings revealed that one water molecule is enough to stabilize the zwitterionic form of sarcosine. Additionally, the higher number of water molecules interacting with Sarcosine shows that neutral and zwitterionic tautomers of sarcosine attained the isoenergetic with four water molecules. [ABSTRACT FROM AUTHOR]

The folding of a recombinant spider silk protein-polymer in the presence of the tri-methylamine osmolytes TMANO and Betaine in 80% H2O is reported. Circular dichroism measurements (CD) reveal an increase in α-helical secondary structure with increasing osmolyte concentrations, as determined by an increase in ellipticity at 222 nm. Consistent with this observation, the signal for random coil sampling, observed at 205 nm, is greatly reduced with increasing trimethylamine. Fluorescence spectra of a single tyrosine positioned within the conserved 33-amino acid repeat primary sequence (of the spider-silk mimetic) complements the conformational changes observed by CD. Importantly, there is a correlation between the number of Alkyl-groups (CH3-) on the amine of the osmolyte and enhanced helicity of the 15-repeat silk-mimetic for the osmolytes tested, ie TMANO, Betaine, Sarcosine and Glycine. These preliminary results are applicable to storing and processing recombinant silk sequences in H2O, an important mile-stone for widespread use of recombinant silk polymers. [ABSTRACT FROM AUTHOR]

In this paper, the flow amperometric enzymatic biosensor based on polished silver solid amalgam electrode for determination of sarcosine in model sample under flow injection analysis conditions is presented. The biosensor works on principle of electrochemical detection of oxygen decrease during enzymatic reaction which is directly proportional to the concentration of sarcosine in sample. The whole preparation process takes about 3 h. The RSD of repeatability of 10 consecutive measurements is 1.6% (csarcosine = 1.0 x 10-4 mol dm-3). Under optimal conditions the calibration dependence was linear in the range 7.5 x 10-6 -5.0 x 10-4 mol dm-3 and limit of detection was 2.0 x 10-6 mol dm-3. [ABSTRACT FROM AUTHOR]

Several years ago, sarcosine received attention as a prostate-cancer marker. Prostate cancer is one of the most widespread types of tumor diseases in men. The prostate-specific antigen is normally used as a marker, and it can only be detected in blood with a sensitivity of approximately 80%. In the present study, dummy molecularly imprinted polymers in microextraction by packed sorbent with on-line liquid chromatography coupled to tandem mass spectrometry was used for the determination of sarcosine in human plasma and urine samples. The polymer network glycine was used for the dummy molecularly imprinted polymers. The selectivity of the method was evaluated using similar prostate-cancer biomarkers. In addition, various parameters affecting the extraction performance were investigated. The method limits of detection and quantification in the plasma and urine were 1.0 and 3.0 ng/mL, respectively. The values of the coefficient of determination were over 0.99 for all runs in the studied concentration range (3.0-10 000 ng/mL). The method recovery was 87 and 89% in plasma and urine, respectively. The intraday and interday precisions of sarcosine in the plasma and urine samples were in the ranges of 4.0-7.1, 3.0-6.3, 2.9-4.7, and 5.0-6.7, respectively. [ABSTRACT FROM AUTHOR]

Sarcosine was recently identified as a differential metabolite that is present in urine in elevated concentration as prostate cancer develops metastases. The aim of this study is to prepare reflectometric interference spectroscopy (RIfS) nanosensors for the detection of sarcosine. Sarcosine imprinted nanoparticles were prepared by two phase miniemulsion polymerization and characterized with transmission electron microscopy, dynamic light scattering, and atomic force microscopy measurements. The glass substrates (10 × 10 mm2) were treated with Piranha solution and incubated in polyethyleneimine solution. The sarcosine imprinted nanoparticles were attached to glass substrates by spin coating of nanoparticle solution. The recognition properties of the nanosensors were evaluated by reflectometric interferometric spectroscopy. To show selectivity of sarcosine imprinted RIfS nanosensor, real-time l-alanine detection was also performed. Sarcosine detection studies were performed from aqueous solution and urine sample. A good linearity was revealed with a correlation coefficient of 0.9622 and a detection limit of 45 nM. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:55-61, 2015 [ABSTRACT FROM AUTHOR]

Glycine is involved in several physiological functions, e.g. as a neurotransmitter in the central nervous system, and sarcosine has been identified as a differential metabolite greatly enhanced during prostate cancer progression and metastasis. Glycine oxidase from Bacillus subtilis ( GO) was engineered with the final aim of producing specific analytical systems to detect these small achiral amino acids. Based on in silico analysis, site-saturation mutagenesis was independently performed at 11 positions: a total of 16 single-point GO variants were analyzed. Significantly improved kinetic parameters were observed on glycine for the A54R, H244K-N-Q-R, Y246W and M261R variants. The introduction of multiple mutations then identified the H244K/M261R variant showing a 5.4-fold increase in maximal activity on glycine. With sarcosine as substrate, a number of single-point variants showed increased maximal activity and/or affinity: the kinetic efficiency was increased 6-fold for the M49L variant. Two GO variants with a high substrate specificity ratio for glycine (versus sarcosine, i.e. H244K GO) or for sarcosine (versus glycine, i.e. M49L GO) combined with high substrate affinity were used to set up a simple fluorescence-based biosensor. This optical sensing assay represents a novel, inexpensive and fast tool to assay glycine or sarcosine concentrations in biological samples (detection limit ≤ 0.5 μ m). [ABSTRACT FROM AUTHOR]

Recently, we developed a selective and efficient method of hydrogen-deuterium exchange (HDX) at the α-carbon (α-C) of sarcosine residue (N-methylglycine) in model peptides [Bąchor et al. J. Mass Spectrom. 2014, 49, 43]. Here, we report the influence of quaternary ammonium (QA) group on HDX at the α-C of sarcosine and N-methylalanine in peptides. The obtained results suggest a significant acceleration of the HDX in sarcosine residue caused by the presence of QA. The effect depends on the distance between the sarcosine residue and QA moiety. The deuterons, introduced at α-C, are resistant to the back-exchange in acidic aqueous solution. The collision induced dissociation of the deuterium-labeled analogs of QA-tagged oligosarcosine peptides without mobile hydrogen revealed the mobilization of the hydrogens localized at α-C of sarcosine residue. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Infinite head-to-tail chains of zwitterions present in the crystals of all amino acids are known to be preserved even after structural phase transitions. In order to understand the role of the N-H...O hydrogen bonds linking zwitterions in these chains in structural rearrangements, the crystal structures of the N-methyl derivatives of glycine ( N-methylglycine, or sarcosine, with two donors for hydrogen bonding; two polymorphs of N, N-dimethylglycine, DMG-I and DMG-II, with one donor for hydrogen bond; and N, N, N-trimethylglycine, or betaine, with no hydrogen bonds) were studied at different pressures. Methylation has not only excluded the formation of selected hydrogen bonds, but also introduced bulky mobile fragments into the structure. The effects of pressure on the systems of the series were compared with respect to distorting and switching over hydrogen bonds and inducing reorientation of the methylated fragments. Phase transitions with fragmentation of the single crystals into fine powder were observed for partially methylated N-methyl- and N, N-dimethylglycine, whereas the structural changes in betaine were continuous with some peculiar features in the 1.4-2.9 GPa pressure range and accompanied by splitting of the crystals into several large fragments. Structural rearrangements in sarcosine and betaine were strongly dependent on the rate of pressure variation: the higher the rate of increasing pressure, the lower the pressure at which the phase transition occurred. [ABSTRACT FROM AUTHOR]

Sarcosine has been identified as a potential prostate cancer marker. To provide determination of this compound, a number of methods are developing. In this study, we optimized a method for its separation by hydrophilic interaction LC with electrochemical detection ( ED). Due to the fact that mobile phases commonly used for this type of separation altered the LODs measured by electrochemical detectors, we applied postcolumn dosing of buffer suitable for ED. The optimized conditions were mobile phase A acetonitrile, mobile phase B water in the ratio A/ B 70:30, with postcolumn addition of mobile phase C (200 mM phosphate buffer pH 9). The optimal mixing ratio was A + B/ C 1:1 with a flow rate of 0.80 mL/min (0.40 + 0.40 mL/min) and detection potential of 1000 mV. Due to the optimization of the parameters for effective separation, which had to meet the optimal parameters of ED, we reached a good resolution for separation also with a good LOD (100 nM). In addition, we successfully carried out sarcosine analysis bound on our modified paramagnetic microparticles with the ability to preconcentrate sarcosine isolated from artificial urine. [ABSTRACT FROM AUTHOR]

The effect of N-methylation on sequence scrambling in the fragmentation of b5 ions has been investigated by studying a variety of peptides containing sarcosine (N-methylglycine). The product ion mass spectra for the b5 ions derived from Sar-A-A-A-Y-A and Sar-A-A-Y-A-A show only minor signals for non-direct sequence ions the major fragmentation reactions occurring from the unrearranged structures. This is in contrast to the b5 ions where the Sar residue is replaced by Ala and sequence scrambling occurs. The b5 ion derived from Y-Sar-A-A-A-A shows a product ion mass spectrum essentially identical to the spectrum of the b5 ion derived from Sar-A-A-A-Y-A, indicating that in the former case macrocyclization has occurred but the macrocyclic form shows a strong preference to reopen to put the Sar residue in the N-terminal position. Similar results were obtained in the comparison of b5 ions derived from A-Sar-A-A-Y-A and Sar-A-A-Y-A-A. The product ion mass spectra of the MH+ ions of Y-Sar-A-A-A-A and A-Sar-A-A-Y-A show substantial signals for non-direct sequence ions indicating that fragmentation of the MH+ ions channels extensively through the respective b5 ions and further fragmentation of these species. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Hydrogens connected to α-carbon ( α-C) of amino acid residues are usually resistant to hydrogen-deuterium exchange (HDX) unless reaction conditions promote racemization. Although N-methylglycine (sarcosine) residue has been found in biologically active peptide such as cyclosporine, to the best of our knowledge, the HDX of α-C protons of this residue was not explored yet. Here, we presented a new and efficient methodology of α-C deuteration in sarcosine residues under basic aqueous conditions. The deuterons, introduced at α-C atom, do not undergo back-exchange in acidic aqueous solution. The electrospray ionization-MS and MS/MS experiments on proposed model peptides confirmed the HDX at α-C and revealed the unexpected hydrogen scrambling in sarcosine-containing peptides. Although the observed HDX of α-C protons is only successful in N-acylglycine when the amide possesses a certain degree of alkylation, it offers a new approach to the analysis of sarcosine-containing peptides such as cyclosporine. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Sarcosine, a potential biomarker of prostate cancer, has drawn great attention in recent years. However, controversial research keeps arising about its role as a biomarker that might come from the two isomers (α-alanine and β-alanine) of sarcosine due to their same molecular weight and similar properties, which could interfere with the accurate detection of sarcosine. In this study, a simple and sensitive method was developed for the detection of sarcosine and the two isomers by LC with ion-trap MS through a novel derivatization reagent N, N′-dicyclohexylcarbodiimide. N, N′-Dicyclohexylcarbodiimide is usually considered as a condensation reagent, however, it was directly used as a derivatization reagent through a rearrangement side reaction in this study. The proposed method not only improved the chromatographic retention behavior of sarcosine and its two isomers, which was a benefit to their separation, but also dramatically enhanced the detection sensitivity of sarcosine, which was more favorable for real sample analysis. The factors affecting the productivity of the derivatization reaction, such as reaction time and amount of derivatization reagent, were systematically optimized. The method shows good linearity ( R2 > 0.99), sensitivity with LODs of sarcosine as low as 1 ng/mL, and repeatability with the RSD < 6.07%. The developed method was applied to the analysis of urine. [ABSTRACT FROM AUTHOR]

Methyl group donors and intermediates of one-carbon metabolism affect DNA synthesis and DNA methylation, and may thereby affect prostate carcinogenesis. Choline, the precursor of betaine, and the one-carbon metabolite sarcosine have been associated with increased prostate cancer risk. Within JANUS, a prospective cohort in Norway ( n = 317,000) with baseline serum samples, we conducted a nested case-control study among 3,000 prostate cancer cases and 3,000 controls. Using conditional logistic regression, odds ratios (ORs) and 95% confidence intervals (CIs) for prostate cancer risk were estimated according to quintiles of circulating betaine, dimethylglycine (DMG), sarcosine, glycine and serine. High sarcosine and glycine concentrations were associated with reduced prostate cancer risk of borderline significance (sarcosine: highest vs. lowest quintile OR = 0.86, CI = 0.72-1.01, ptrend = 0.03; glycine: OR = 0.83, CI = 0.70-1.00, ptrend = 0.07). Serum betaine, DMG and serine were not associated with prostate cancer risk. However, individuals with a high glycine/serine ratio were at decreased prostate cancer risk (OR = 0.74, CI = 0.69-0.85, ptrend < 0.001). This population-based study suggested that men with high serum sarcosine or glycine concentrations have modestly reduced prostate cancer risk. Ratios of metabolites reflecting one-carbon balance may be associated with prostate cancer risk, as demonstrated for the glycine/serine ratio, and should be explored in future studies. [ABSTRACT FROM AUTHOR]

The smectite clay, montmorillonite, can be found in many soils throughout the world. In addition to its importance in agriculture and soil remediation, montmorillonite has extensive applications in industry both in its natural form and as a component of composite materials. The adsorptive properties of montmorillonite have been explored in relation to its interactions with the common herbicide glyphosate. This herbicide, when exposed to microorganisms in the soil is degraded, forming two products: aminomethylphosphonic acid (AMPA) and sarcosine. The atomic-level interactions of these compounds with the montmorillonite interlayer surfaces are studied here using molecular mechanics. The final outcomes of these calculations are analyzed in terms of the proximity of the montmorillonite surface to the moieties of the degradation products. The phosphonate moiety was found to be the most important source of interactions for AMPA, while for sarcosine there was an even distribution between the amino and carboxylic moieties, and Na+ ion mediated surface complexes. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 [ABSTRACT FROM AUTHOR]

Mixtures of organic osmolytes occur in cells of many organisms, raising the question of whether their actions on protein stability are independent or synergistic. To investigate this question it is desirable to develop a system that permits evaluation of the effect of one osmolyte on the efficacy of another to either force-fold or denature a protein. A means of evaluating the efficacy of an osmolyte is provided by its m-value, an experimental quantity that measures the ability of the osmolyte to force a protein to unfold or fold. An experimental system is presented that enables evaluations of the m-values of osmolytes in the presence and absence of a second osmolyte. The experimental system involves use of a marginally stable protein in 10 mM buffer (pH 7, 200 mM salt, and 34°C) that is at the midpoint of its native to denatured transition. These conditions enable determination of m-values for protecting and denaturing osmolytes in the presence and absence of a second osmolyte, permitting assessment of the extent to which the two osmolytes affect each other's efficacy. The two osmolytes investigated in this work are the denaturing osmolyte, urea, and the protecting osmolyte, sarcosine. Results show unequivocally that neither osmolyte alters the efficacy of the other in forcing the protein to fold or unfold-the osmolytes act independently on the protein despite their combined concentrations being in the multi-molar range. These osmolytes avoid altering one another's efficacy at these high concentrations because the number of osmolyte interaction sites on the protein is large and the binding constants are quite small. Consequently, the site occupancies are low enough in number that the two osmolytes neither compete nor cooperate in interacting with the protein. [ABSTRACT FROM AUTHOR]

The nucleotide sequences of two cloned DNA fragments containing the structural genes of heterotetrameric sarcosine oxidase (soxBDAG) and dimethylglycine dehydrogenase (dmg) from Arthrobater spp. 1-IN and Arthrobacter globiformis, respectively, have been determined. Open reading frames were identified in the soxBDAG operon corresponding to the four subunits of heterotetrameric sarcosine oxidase by comparison with the N-terminal amino-acid sequences and the subunit relative molecular masses of the purified enzyme. Alignment of the deduced sarcosine oxidase amino-acid sequence with amino-acid sequences of functionally related proteins indicated that the arthrobacterial enzyme is highly homologous to sarcosine oxidase from Corynebacterium P-1. Deletion and expression analysis, and alignment of the deduced amino-acid sequence of the dmg gene, showed that dmg encodes a novel dimethylglycine oxidase, which is related to eukaryotic dimethylglycine dehydrogenase, and contains nucleotide-binding, flavinylation and folate-binding motifs. The recombinant dimethylglycine oxidase was purified to homogeneity and characterized. The DNA located upstream and downstream of both the soxBDAG and dmg genes is predicted to encode enzymes involved in the tetrahydrofolate-dependent assimilation of methyl groups. Based on the sequence analysis reported herein, pathways are proposed for glycine betaine catabolism in Arthrobacter species, which involve the identified folate-dependent enzymes. [ABSTRACT FROM AUTHOR]

Brucellosis is an important zoonosis, and serological surveillance is essential to its control. However, cross-reactions of attenuated live cells of Brucella abortus strain S-19 and B. melitensis strain Rev-1 with Yersinia enterocolitica O9 or vaccinated animal sera interfere with accurate serological diagnosis by the Rose Bengal test (RBT). Therefore, we used ELISA with sarcosine extracts from the virulent B. abortus strain 544 to eliminate false-positives among RBT positive-sera. A total of 697 serum samples were collected in Mongolia from humans and animals in 23 nomadic herds. The herds were classified into three groups as brucellosis-endemic (BE), brucellosis-suspected (BS), or Brucella-vaccinated (BV). The number of 295 animals (43.0%) was positive by RBT, but 206 (69.8%) of these were positive according to ELISA; therefore, 30.2% of the RBT-positive sera were found to be false positives. The false positive samples for RTB represent 4.1%, 27.4%, and 68.2% of the animals from the BE, BS, and BV herds, respectively. In addition, 32% of RBT-positive human sera were also false positives. Thus, our ELISA would be more specific than RTB and useful for epidemiological surveillance for brucellosis.