ESI/FTICR

Shen, Y., Tolic, N., Zhao, R., Pasa-Tolic, L., Li, L., Berger, S.J., Harkewicz, R., Anderson, G.A., Belov, M.E., Smith, R.D. (2001). High-throughput proteomics using high efficiency multiple-capillary liquid chromatography with on-line high performance ESI FTICR mass spectrometry. Anal. Chem. 73, 3011-3021. 

Kalkhof, S., Haehn, S., Ihling, C., Smyth, N., and Sinz, A. (2005b) Probing laminin self-interaction using isotope-labeled cross-linkers and ESI-FTICR mass spectrometry. Poster, Pierce Biotechnology web site. 

Sinz, A., Kalkhof, S., and Ihling, C. (2005) Mapping protein interfaces by a trifunctional cross-linker combined with MALDI-TOF and ESI-FTICR mass spectrometry. /. Am. Soc. Mass Spectrom. 16(12), 1921-1931. 

Fig. 10.1 Effect of buffer composition on the ESI-FTICR-MS spectrum of myoglobin. The spectrum in (a) was acquired from a solution containing 2 pM myoglobin in 50% MeOH, 49% H2O, and 1% HOAc. Peaks corresponding to apomyoglobin and free heme dominate the spectrum. The spectrum in (b) was acquired from a solution...

Fig. 10.7 ESI-FTICR mass spectra of three RNA targets at 2.5 pM each screened against 11 compounds at 25 pM each. The percent complexes and one-point values are shown for each ligand complex, (a) An example of a ligand that specifically binds target 2. (b) An example of a ligand that nonspecifically binds to all targets.

R. H. High performance ESI-FTICR mass spectrometry as a high throughput screen to identify RNA-binding ligands. Ahstr Pap Am Chem Soc 2001, 221, ANYL-197. 

Carbonic anhydrase [17] Acyl hydrazone exchange <300 ESI-FTICR-MS... 

Table 7.2 Molecular weights for CA ll-bound ligands identified from in situ screening of the DCL by ESI-FTICR-MS.

The mass measurement errors also depend on a large number of factors. A typical measurement error of 0.01 % can be obtained routinely. However, these errors can be higher than 0.1 % in the worst case (MALDI-LTOF) or to be lower than 0.0001 % in the best case (ESI-FTICR). 

Figure 1. Characterisation of synthetic cAPP polypeptides by FTICR-MS and FTICR-MS/MS. (A) ESI-FTICR spectrum of APP(723-767) (0. 1 xg/p,l) showing molecular ions with 4+ to 8+ charge states (B) ESI-FTICR-MS/MS of 6+ charged ion (0.01 M-g/p-l) at capillary exit voltage of 130 V.

J.E. Bruce, G.A. Anderson, J. Wen, R. Harkewicz, R.D. Smith, High-mass-measurement accuracy and 100% sequence coverage of enzymatically digested bovine serum albumin from an ESI-FTICR mass spectrum. Anal. Chem., 71 (1999) 2595. 

Direct-infusion MS is a very interesting approach, especially when sample characteristics allow MS analysis with minimum sample treatment. Thus, ESI can be used to directly ionize analytes in liquid samples in a high electric field. A small flow of the liquid sample is conducted through a capillary to the high electric field for ESI. Usually, sample solutions must be carefully cleaned and filtered to avoid potential capillary blocking. Following this idea, direct-infusion ESI-FTICR (Fourier transform ion cyclotron resonance) MS of a coffee drink combined with partial least-squares multivariate statistical analysis was successfully employed to predict the blend composition of commercial coffee varieties (28). In a different work, minimal sample manipulation was carried out to obtain detailed molecular composition of edible oils and fats analyzed by flow-injection ESI-Orbitrap MS for quality assessment and authenticity control purposes (29). Commonly, when using direct infusion approaches, sample needs to be treated to dissolve the compounds of interest in the appropriate solvent. 

Figure 9 (a) ESI-FTICR broad-band mass spectrum of a library thought to be H-Gly-pTyr-Xxx-Xxx-Xxx-Cys-OH where Xxx can be any one of the naturally occurring amino acids with the exception of Cys and Trp. (b) A simulated mass spectrum of H-Gly-pTyr-Xxx-Xxx-Xxx-Cys-OH. (c) A computer-simulated spectrum of library H-Xxx-Xxx-Xxx-Cys-OH where Xxx can be any one of the naturally occurring amino acids with the exception of Cys and Trp. (Reprinted from Ref. 92.)... 

JP Nawrocki, M Wigger, CH Watson, SA Benner, JR Eyler. Characterization of combinatorial libraries using ESI-FTICR mass spectrometry. Proceedings of the 45th ASMS Conference on Mass Spectrometry and Allied Topics, Palm Springs, CA, 1997, p. 1256. 

Fig. 5.8. ESI FTICR mass spectrum of the supramolecular rhomb s (S,S,S,S) enantiomer. The intense signal at m/z 662 represents the doubly-charged complex [M—2 HNO3-2 NOs]. The insets show the experimental (top) and calculated (bottom) isotope patterns of the doubly-charged ion [M—2 HNO3-2 NO3]2 (right inset) and the triply-charged ion [M—I—IN O3—3 NO3] + (left inset). The inset of the doubly-charged species at m/z 662 is superimposed by another isotope pattern of a triply-charged 3 3 complex, that is also included in the calculation.

FIGURE 2.3 (A) ESI-FTICR mass spectrum of a mixture of carbonic anhydrase II (CAII) and combinatorial library (289 components, 1). (B) MS-MS spectrum of the isolated complex of ions [CAII + Zn + 1] ". The expanded view shows the region of the singly charged inhibitors l , and the doubly expanded region shows the high resolution achieved in the experiment and the amino acid residue composition of the inhibitor ions. (Reprinted from Gao et al. [18], used with permission. Copyright 1996 by the American Chemical Society.)... 

ESI-FTICR AS A HIGH THROUGHPUT DRUG DISCOVERY PLATFORM... 

---