High-performance Liquid Chromatography/electrospray Ionization Mass Spectrometry (high-performance + liquid_chromatography_ionization_mass_spectrometry)

Distribution by Scientific Domains


Selected Abstracts


Advanced glycation end products: a highly complex set of biologically relevant compounds detected by mass spectrometry,

JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 4 2001
Annunziata Lapolla
Abstract Structural information on ,AGE-peptides,' a class of substances belonging to advanced glycation end products (AGE) and originating by proteolysis of glycated proteins, was gained through various analytical approaches on the mixture produced by proteinase K digestion of in vitro glycated bovine serum albumin. Both matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and high-performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI-MS) were employed, and the results were compared with those from conventional spectroscopic methods (UV, fluorescence, gel permeation). The data acquired by the various techniques all depict the digestion mixtures as highly complex, with components exhibiting molecular mass in the range 300,3500 Da. In the analysis of HPLC/ESI-MS data, identification of AGE-peptides was facilitated by 3D mapping. Structural information was gained by means of multiple mass spectrometric experiments. Copyright 2001 John Wiley & Sons, Ltd. [source]


Detection and characterization by high-performance liquid chromatography and mass spectrometry of two truncated goat ,s2 -caseins

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 7 2006
Vincenzo Cunsolo
The identification and characterization of truncated forms of goat ,s2 -Cn variants A and E are reported. The two proteins, which have experimental Mr values of 24,183 and 24,227,Da, were detected as minor components in a goat milk sample from an autochthonous breed of southern Italy, ,Rossa Mediterranea', by reversed-phase high-performance liquid chromatography/electrospray ionization mass spectrometry (RP-HPLC/ESI-MS). Characterization of the amino acid sequences, performed by coupling trypsin digestion with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), RP-HPLC/ESI-MS and tandem mass spectrometry (MS/MS), demonstrated that the polypeptide chains correspond to the 1-204 sequence of mature ,s2 -Cn variant A (component with Mr of 24,183,Da) and E (component with Mr of 24,227,Da), respectively. These components seem to be the product of a differential splicing of pre-messenger RNA during the translation process of the ,s2 -Cn variants A and E. Copyright 2006 John Wiley & Sons, Ltd. [source]


Identification of heat-induced degradation products from purified betanin, phyllocactin and hylocerenin by high-performance liquid chromatography/electrospray ionization mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 18 2005
Kirsten M. Herbach
Betanin, phyllocactin (malonylbetanin) and hylocerenin (3-hydroxy-3-methylglutarylbetanin) were isolated from purple pitaya (Hylocereus polyrhizus [Weber] Britton & Rose) juice, and their degradation products generated by heating at 85C were subsequently monitored by high-performance liquid chromatography/electrospray ionization tandem mass spectrometry. Thermal degradation of phyllocactin and hylocerenin in purified solution excluding the alleged protective effects by the juice matrix is reported for the first time. Betanin was predominantly degraded by hydrolytic cleavage, while decarboxylation and dehydrogenation were of minor relevance. In contrast, hylocerenin showed a strong tendency to decarboxylation and dehydrogenation, hydrolytic cleavage of the aldimine bond occurring secondarily. Phyllocactin degradation was most complex because of additional decarboxylation of the malonic acid moiety as well as generation and subsequent degradation of betanin due to phyllocactin demalonylation. Upon prolonged heating, all betacyanins under observation formed degradation products characterized by an additional double bond at C2C3. Hydrolytic cleavage of the aldimine bond of phyllocactin and hylocerenin yielded previously unknown acylated cyclo -dopa derivatives traceable by positive ionization, while application of ESI(,) facilitated the detection of a glycosylated aminopropanal derivative and dopamine, which have never been described before as betanin degradation products. Copyright 2005 John Wiley & Sons, Ltd. [source]


Determination of Xipamide metabolite in human urine by high-performance liquid chromatography/diode-array detection, high-performance liquid chromatography/electrospray ionization mass spectrometry and gas chromatography/mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 22 2004
Yunje Kim
The original article to which this Erratum refers was published in Rapid Commun. Mass Spectrom. 2004; 18: 2505,2512 [source]


Identification and characterization of a new , -casein variant in goat milk by high-performance liquid chromatography with electrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 17 2004
Francesco Galliano
A new variant of , -casein was detected in the casein fraction obtained from milk of a goat belonging to an autochthonous breed of southern Italy, ,Argentata dell'Etna'. Reversed-phase high-performance liquid chromatography/electrospray ionization mass spectrometry (RP-HPLC/ESI-MS) analysis indicated that the new , -casein variant, here named D, has a Mr 15,Da higher than that of variant C previously described. The modification in the amino acid sequence responsible for the 15,Da difference in Mr between variants C and D was determined by coupling trypsin digestion with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and RP-HPLC/ESI-MS, and it was demonstrated that it is due to the point mutation Val207,,,Asn207. The phosphorylation pattern of the new variant D was shown to be identical to that of variant C, as the protein shows two phosphorylation levels, 5 and 6P, occurring with comparable relative abundances. Ser35 was determined as one of the phosphorylation sites, whereas the others were probably analogous to those determined previously for the , -Cn variant C, at Thr12 and Ser15, 17,19. The results reported here indicate that the combined use of RP-HPLC/ESI-MS, MALDI-TOFMS and MS/MS represents a powerful tool for the detection and characterization of minor components present in complex protein mixtures. Copyright 2004 John Wiley & Sons, Ltd. [source]


Analysis of native and chemically modified oligonucleotides by tandem ion-pair reversed-phase high-performance liquid chromatography/electrospray ionization mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 7 2003
Kenneth J. Fountain
Ion-pair reversed-phase high-performance liquid chromatography (IP-RP-HPLC) was utilized in tandem with negative-ion electrospray ionization time-of-flight mass spectrometry (ESI-TOFMS) for the analysis of native and chemically modified oligonucleotides. Separation was performed on a 1.0,,50,mm column packed with porous C18 sorbent with a particle size of 2.5,,m and an average pore diameter of 140 . A method was developed which maximizes both chromatographic separation and mass spectrometric sensitivity using an optimized buffer system containing triethylamine and 1,1,1,3,3,3-hexafluoro-2-propanol with a methanol gradient. The ESI-TOFMS tuning parameters were also optimized in order to minimize in-source fragmentation and achieve the best sensitivity. Analyses of native, phosphorothioate, and guanine-rich oligonucleotides were performed by LC/MS. Detection limits were at sub-picomole levels with an average mass accuracy of 125,ppm. The described method allowed for the LC/MS analysis of oligonucleotides up to 110mer in length with little alkali cation adduction. Since sensitive detection of oligonucleotides was achieved with ultraviolet (UV) detection, we utilized a combination of UV-MS for quantitation (UV) and characterization (MS) of oligonucleotides and their failure sequence fragments/metabolites. Copyright 2003 John Wiley & Sons, Ltd. [source]