02720nas a2200289   4500008004100000022001400041245015100055210006900206260008100275300002200356490000700378520163500385653001302020653001402033653001402047653002102061653001002082653002202092100003902114700002502153700002502178700002002203700002302223700002902246700002502275856013002300       2016                        eng d  a1542-641600aTargeted quantification of N-1-(carboxymethyl) valine and N-1-(carboxyethyl) valine peptides of beta-hemoglobin for better diagnostics in diabetes0 aTargeted quantification of N1carboxymethyl valine and N1carboxye  a236 GRAYS INN RD, FLOOR 6, LONDON WC1X 8HL, ENGLANDbBIOMED CENTRAL LTDcMAR  aArticle Number: 70 v133 a<p>Background: N-1-(Deoxyfructosyl) valine (DFV) beta-hemoglobin (beta-Hb), commonly referred as HbA1c, is widely used diagnostic marker in diabetes, believed to provide glycemic status of preceding 90-120 days. However, the turnover of hemoglobin is about 120 days, the DFV-beta-Hb, an early and reversible glycation product eventually may undergo irreversible advanced glycation modifications such as carboxymethylation or carboxyethylation. Hence quantification of N-1-(carboxymethyl) valine (CMV) and N-1-(carboxyethyl) valine (CEV) peptides of beta-Hb would be useful in assessing actual glycemic status. Results: Fragment ion library for synthetically glycated peptides of hemoglobin was generated by using high resolution-accurate mass spectrometry (HR/AM). Using parallel reaction monitoring, deoxyfructosylated, carboxymethylated and carboxyethylated peptides of hemoglobin were quantified in clinical samples from healthy control, pre-diabetes, diabetes and poorly controlled diabetes. For the first time, we report N-1-beta-valine undergoes carboxyethylation and mass spectrometric quantification of CMV and CEV peptides of beta-hemoglobin. Carboxymethylation was found to be the most abundant modification of N-1-beta-valine. Both CMV-beta-Hb and CEV-beta-Hb peptides showed better correlation with severity of diabetes in terms of fasting glucose, postprandial glucose and microalbuminuria. Conclusions: This study reports carboxymethylation as a predominant modification of N-1-beta-valine of Hb, and quantification of CMV-beta-Hb and CEV-beta-Hb could be useful parameter for assessing the severity of diabetes.</p>10aDiabetes10aDiagnosis10aGlycation10aGlycemic control10aHbA1c10aMass spectrometry1 aJagadeeshaprasad, Mashanipalya, G.1 aBatkulwar, Kedar, B.1 aMeshram, Nishita, N.1 aTiwari, Shalbha1 aKorwar, Arvind, M.1 aUnnikrishnan, Ambika, G.1 aKulkarni, Mahesh, J.  uhttps://library.ncl.res.in/content/targeted-quantification-n-1-carboxymethyl-valine-and-n-1-carboxyethyl-valine-peptides-beta01499nas a2200145   4500008004100000245007600041210006900117300001200186520093800198100002901136700002301165700003901188700002501227856010101252       2017                        eng d00aTargeted quantification of the glycated peptides of human serum albumin0 aTargeted quantification of the glycated peptides of human serum   a403-4163 a<p>Glycated human serum albumin (HSA) serves as an important marker for monitoring the glycemic status. Developing methods for unambiguous identification and quantification of glycated peptides of HSA using high-throughput technologies such as mass spectrometry has a great clinical significance. The following protocol describes the construction of reference spectral libraries for Amadori-modified lysine (AML), N(ε)-(carboxymethyl) lysine (CML)-, and N(ε)-(carboxyethyl)lysine (CEL)-modified peptides of synthetically modified HSA using high-resolution mass spectrometers. The protocol also describes work flows, for unambiguous identification and quantification of glycated modified peptides of HSA in clinical plasma using standard spectral libraries by various mass spectrometry approaches such as parallel reaction monitoring (PRM), sequential window acquisition of all theoretical fragment ion spectra (SWATH), and MSE.</p>1 aGarikapati, Vannuruswamy1 aKorwar, Arvind, M.1 aJagadeeshaprasad, Mashanipalya, G.1 aKulkarni, Mahesh, J.  uhttps://library.ncl.res.in/content/targeted-quantification-glycated-peptides-human-serum-albumin