MALDI PSD spectrum

MIKES of amine molecular ions in the context of H/D isotope effects CID spectrum of toluene molecular ion on a magnetic sector instrument MALDI-PSD spectrum of a peptide... 

Example The PSD-MALDI-TOF spectrum of the [M+Na]" ion, m/z 1418.9, of high-mannose A-linked glycan (Man)6(GlcNAc)2 from chicken ovalbumin recorded from DHB shows distinct cleavages of the branched carbohydrate skeleton (Fig. 10.16). [134]... 

M+H)+ of a derivative of the linear pentadecapeptide and antibiotic Val-gramicidicin A, a transmembrane protein this derivative has structure formyl-NH-V-G-A-L-A-V-V-V-W-L-W-L-W-L-W-ethanolamine. The CID (collision-induced dissociation) spectrum is very similar to a MALDI/TOF spectrum. Figure 11.10 shows the PSD of ACTH, the adenocorticotropic hormone. 

Figure 6. MALDI mass spectrum of fraction 13 from RP-HPLC. The H,K-ATPase-enriched vesicles were trypsinized and centrifuged to separate supernatant from pellet. The supernatant was subjected to RP/HPLC and individual fractions collected and subjected to MALDI/MS. The MALDI mass spectrum (reflectron-ion mode) was obtained using a-cyano-4-hydroxy cinnamic acid as a matrix (Panel A). The signals were assigned to a-subunit peptides (Table 2). The signal at m/z 1798, indicated by an arrow was next subjected to PSD-analysis. The PSD-spectrum of MH+ 1798.4 is shown in Panel B. Only the peaks for the b and y fragment ions are labeled. The deduced amino acid sequence is shown at the top of the panel.

Fig. 16.19. Mass spectrometry of WIN antiviral drug, (a) DIOS-MS spectrum ofWIN deposited upon porous silicon. Inset DIOS-PSD-MS spectrum of WIN. (b) MALDI-MS spectrum of WIN dispersed in a-cyano-4-hydroxycinnamic acid (HCCA). (c) Attempted...

The first MALDI mass spectrometers that were able to perform MS/MS experiments applied the PSD principle. One major drawback preventing its broad application was the necessity for scanning the reflector voltage. The final mass spectrum had to be assembled from a series of single mass spectra recorded at different reflector voltages. Thus, the number of experiments (and especially the calibration) made MALDI-PSD very time consuming, meaning that only a few examples of... 

The PSD MALDI spectrum of Des-Arg1 bradykinine, whose sequence is PPGF-SPFR. The starred peaks correspond to the loss of a 28 Da fragment. Reproduced (modified) from Rouse J.C., Yu W. and Martin S.A., J. Am. Mass Spectrom., 6, 822-835, 1996, with permission. 

PSD-MALDI-TOF mass spectrum of the trimer from poly(bisphenol-A carbonate) (PC). (Reprinted with permission from Ref. 242)... 

Figure 11.9. (a) PSD mass spectrum of the MALDI-produced [M + Na]+ ions of a high-mannose glycan (Man)6(GlcNAc)2 that was released from ovalbnmin, and (b) the fragmentation scheme. (Reproduced from ref. 28 by permission of Elsevier, copyright 2000 American Society for Mass Spectrometry.)... 

FIGURE 8.16 Three views of an unknown protein obtained by MALDI-TOF mass spectrometry (a) linearmode mass spectrum of the intact protein, (b) mass map of the tryptic peptides derived from the unknown protein, and (c) PSD mass spectrum of peptide I from the mixture in (b). (Reprinted with permission from reference I i). 

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