Electrospray ionization

The carbohydrate moieties of glycosphingolipids from eggs of the human parasite,Schistosoma mansoni,wereenzy-matically released, labelled with 2-aminopyridine (PA), fractionated and analysed by linkage analysis, partial hydrolysis, enzymatic cleavage, matrix-assisted laser desorption/ionization time-of-¯ight mass spectrometry and nano-electrospray ionization mass spectrometry.

13p research12 23-04-2013 25 2   Download

Lipopolysaccharide (LPS) ofEscherichia colistrain2513 (R4 core-type) yielded after alkaline deacylation one major oligosaccharide by high-performance anion-exchange chro-matography (HPAEC) which had a molecular mass of 2486.59 Da as determined by electrospray ionization mass spectrometry. This was in accordance with the calculated molecular mass of a tetraphosphorylated dodecasaccharide of the composition shown below.

10p tumor12 22-04-2013 38 3   Download

Liquid chromatography mass spectrometry (LC-MS) is a valuable tool in the analysis of proteins and peptides.The combination of LC-MS with different fragmentation methods provides sequence information on components in complex mixtures.In this work, on-line packed capillary LC electrospray ionization Fourier transform ion cyclotron resonance MS was combined with two complementary fragmentation techniques, i.e.

7p tumor12 20-04-2013 45 2   Download

Six ribosomal proteins are specific to higher plant chloro-plast ribosomes [Subramanian,A.R. (1993)TrendsBiochem. Sci.18, 177–180]. Three of them have been fully character-ized [Yamaguchi, K., von Knoblauch, K. & Subramanian, A. R. (2000) J. Biol. Chem.275, 28455–28465; Yamaguchi, K. &Subramanian, A. R. (2000) J. Biol. Chem.275, 28466– 28482]. The remaining three plastid-specific ribosomal pro-teins (PSRPs), all on the small subunit, have now been characterized (2D PAGE, HPLC,N-terminal/internal pep-tide sequencing, electrospray ionization MS, cloning/ sequencing of precursor cDNAs). ...

16p tumor12 20-04-2013 40 2   Download

Noncovalent binding of thioxylo-oligosaccharide inhibitors, methyl 4-thio-a-xylobioside (S-Xyl2-Me), methyl 4,4 II -dithio-a-xylotrioside (S-Xyl3-Me), methyl 4,4 II ,4 III -trithio-a-xylotetroside (S-Xyl4-Me), and methyl 4,4 II , 4 III ,4 IV -tetrathio-a-xylopentoside (S-Xyl5-Me), to three family 11 endo-1,4-b-xylanases from Trichoderma reesei(TRX I and TRX II) and Chaetomium thermophilum (CTX) was characterized using electrospray ionization Fourier transform ion cyclotron resonance (FT-ICR) MS and X-ray crys-tallography. ...

17p awards 06-04-2013 38 3   Download

Saccharomyces cerevisiaepossesses two glycogenin isoforms (designated as Glg1p and Glg2p) that both contain a con-served tyrosine residue, Tyr232. However, Glg2p possesses an additional tyrosine residue, Tyr230 and therefore two potential autoglucosylation sites. Glucosylation of Glg2p was studied using both matrix-assisted laser desorption ionization and electrospray quadrupole time of flight mass spectrometry. Glg2p, carrying a C-terminal (His6) tag, was produced inEscherichia coliand purified.

12p awards 05-04-2013 37 4   Download

The molecular masses of macromolecules and subunits of the extracellular hemoglobin from the fresh-water crustaceanDaphnia magnawere deter-mined by analytical ultracentrifugation, multiangle laser light scattering and electrospray ionization mass spectrometry.

18p inspiron33 25-03-2013 42 5   Download

ESI greatly enhanced the ability to characterize protein and peptides by MS.
ESI requires the sample of interest to be in solution- flow in to the ionization source region.
To ionize the sample, high voltage is applied, result in the sample becoming positively or negatively charged; however, positive ionization is used primarily in the analysis proteins and peptides.
As it exits the spray tip, the solution produces submicrometer-sized droplets containing both solute and analyte ions. The sample is then desorbed of solute prior to entering the analyzer region....

76p caubebimu 13-01-2013 48 7   Download

Ion hóa bằng phun điện ESI (Electrospray Ionization) LC-MS • Tách bằng LC Xác định bằng MS • Khó khăn: loại ảnh hưởng của dung môi và các thành phần trong pha động; không có thư viện phổ • Để ghép nối giữa LC và MS: • giao diện ion hoá hoá học ở áp suất thường (atmospheric pressure chemical ionisation)

6p zues05 23-06-2011 190 70   Download

Các nhà khoa học Mỹ khẳng định cảnh sát có thể phát hiện dấu vết của heroin, cocaine, cần sa và thậm chí thuốc nổ trên một dấu vân tay. Một nhóm chuyên gia tại đại học Purdue, West Lafayette, bang Indiana (Mỹ) đã sử dụng một kỹ thuật có tên DESI (desorption electrospray ionization), theo đó người ta phun một hợp chất hóa học hòa tan lên bề mặt dấu vân tay rồi phân tích các giọt dung dịch nằm rải rác trên dấu vân bằng phương pháp quang phổ học....

10p halinh 24-03-2011 352 90   Download