02436nas a2200241 4500008004100000022001400041245011500055210006900170260011000239300001400349490000600363520149000369100002701859700001701886700002101903700002001924700002101944700002501965700002101990700002302011700003102034856012902065 2014 eng d a1759-966000aMatrix-assisted laser desorption/ionization mass spectrometry analysis of dimethyl arginine isomers from urine0 aMatrixassisted laser desorptionionization mass spectrometry anal aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAPR a4602-46090 v63 a

Isomeric asymmetric and symmetric dimethyl arginine (ADMA and SDMA respectively) residues are excreted in urine and are putative markers of cardiovascular and chronic kidney diseases. In this work, we demonstrate simultaneous and quantitative detection of endogeneous ADMA and SDMA from urine samples of healthy subjects using MALDI-TOF MS without any chromatographic separation. The DMA isomers yielded [M + H](+) ions along with their product ions formed due to MALDI in-source fragmentation. The precursor ions were validated using MALDI-TOF MS/MS as well as direct injection ESI-Q-TOF MS/MS. ADMA and SDMA generated unique product ions at similar to m/z 46 and similar to m/z 172 respectively in the MS-mode itself. These were advantageously used for full scan-mode absolute quantification of the isomeric metabolites. The m/z observed for all the ions was within 10 ppm mass accuracy. The calibration method was established by generating internal standard normalized peak area-based concentration response curves using synthetic standards. Good linearities (R-2 > 0.95) with acceptable intra-assay, inter-assay variation (within 15% RSD) and excellent recoveries were observed for quality control samples. Finally, endogeneous concentrations of the metabolites were determined in urine from healthy subjects (n = 11). ADMA and SDMA were found to be in the range of 1.6-8 mu M and 2.9-9.1 mu M in urine and were in agreement with previously reported physiological levels.

1 aBhattacharya, Nivedita1 aSingh, Ajeet1 aGhanate, Avinash1 aPhadke, Gayatri1 aParmar, Dharmesh1 aDhaware, Deepika, G.1 aBasak, Trayambak1 aSengupta, Shantanu1 aPanchagnula, Venkateswarlu uhttps://library.ncl.res.in/content/matrix-assisted-laser-desorptionionization-mass-spectrometry-analysis-dimethyl-arginine-002373nas a2200193 4500008004100000022001400041245006600055210006600121260009100187300001300278490000700291520167900298100002601977700001602003700002102019700002602040700001902066856009402085 2015 eng d a1932-620300aEngineering proteins for thermostability with iRDP web server0 aEngineering proteins for thermostability with iRDP web server a1160 BATTERY STREET, STE 100, SAN FRANCISCO, CA 94111 USAbPUBLIC LIBRARY SCIENCEcOCT ae01394860 v103 a

Engineering protein molecules with desired structure and biological functions has been an elusive goal. Development of industrially viable proteins with improved properties such as stability, catalytic activity and altered specificity by modifying the structure of an existing protein has widely been targeted through rational protein engineering. Although a range of factors contributing to thermal stability have been identified and widely researched, the in silico implementation of these as strategies directed towards enhancement of protein stability has not yet been explored extensively. A wide range of structural analysis tools is currently available for in silico protein engineering. However these tools concentrate on only a limited number of factors or individual protein structures, resulting in cumbersome and time-consuming analysis. The iRDP web server presented here provides a unified platform comprising of iCAPS, iStability and iMutants modules. Each module addresses different facets of effective rational engineering of proteins aiming towards enhanced stability. While iCAPS aids in selection of target protein based on factors contributing to structural stability, iStability uniquely offers in silico implementation of known thermostabilization strategies in proteins for identification and stability prediction of potential stabilizing mutation sites. iMutants aims to assess mutants based on changes in local interaction network and degree of residue conservation at the mutation sites. Each module was validated using an extensively diverse dataset. The server is freely accessible at http://irdp.ncl.res.in and has no login requirements.

1 aPanigrahi, Priyabrata1 aSule, Manas1 aGhanate, Avinash1 aRamasamy, Sureshkumar1 aSuresh, C., G. uhttps://library.ncl.res.in/content/engineering-proteins-thermostability-irdp-web-server-102464nas a2200301 4500008004100000022001400041245009900055210006900154260000800223300000900231490000700240520142600247100002601673700002701699700002201726700002301748700002601771700002101797700002701818700002301845700004101868700002201909700002301931700002301954700002701977700003102004856012702035 2020 eng d a2045-232200aPlausible diagnostic value of urinary isomeric dimethylarginine ratio for diabetic nephropathy0 aPlausible diagnostic value of urinary isomeric dimethylarginine  cFEB a29700 v103 a

Altered circulatory asymmetric and symmetric dimethylarginines have been independently reported in patients with end-stage renal failure suggesting their potential role as mediators and early biomarkers of nephropathy. These alterations can also be reflected in urine. Herein, we aimed to evaluate urinary asymmetric to symmetric dimethylarginine ratio (ASR) for early prediction of diabetic nephropathy (DN). In this cross-sectional study, individuals with impaired glucose tolerance (IGT), newly diagnosed diabetes (NDD), diabetic microalbuminuria (MIC), macroalbuminuria (MAC), and normal glucose tolerance (NGT) were recruited from Dr. Mohans' Diabetes Specialties centre, India. Urinary ASR was measured using a validated high-throughput MALDI-MS/MS method. Significantly lower ASR was observed in MIC (0.909) and MAC (0.741) in comparison to the NGT and NDD groups. On regression models, ASR was associated with MIC [OR: 0.256; 95% CI: 0.158-0.491] and MAC [OR 0.146; 95% CI: 0.071-0.292] controlled for all the available confounding factors. ROC analysis revealed ASR cut-point of 0.95 had C-statistic of 0.691 (95% CI: 0.627-0.755) to discriminate MIC from NDD with 72% sensitivity. Whereas, an ASR cut-point of 0.82 had C-statistic of 0.846 (95% CI: 0.800 - 0.893) had 91% sensitivity for identifying MAC. Our results suggest ASR as a potential early diagnostic biomarker for DN among the Asian Indians.

1 aParmar, Dharmeshkumar1 aBhattacharya, Nivedita1 aKannan, Shanthini1 aVadivel, Sangeetha1 aPandey, Gautam, Kumar1 aGhanate, Avinash1 aRagi, Nagarjuna, Chary1 aPrabu, Paramasivam1 aPramodkumar, Thyparambil, Aravindaks1 aManickam, Nagaraj1 aMohan, Viswanathan1 aSripadi, Prabhakar1 aKuppan, Gokulakrishnan1 aPanchagnula, Venkateswarlu uhttps://library.ncl.res.in/content/plausible-diagnostic-value-urinary-isomeric-dimethylarginine-ratio-diabetic-nephropathy