High sensitivity mass spectrometric determination of peptides: Direct analysis of aqueous solutions

Caprioli, Richard M.; Fan, Terry

doi:10.1016/s0006-291x(86)80151-6

Cited by 56 publications

(7 citation statements)

References 3 publications

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“…Increasing the amount of water and decreasing the amount of glycerol in the sample appear to bolster analyte ion abundances and diminish matrix ion abundances significantly. This result is analogous to the observations of Caprioli while using the continuous flow FAB probe (17). Another difference in results obtained from the two sample compositions represented in Figure 1 involves the time dependence of the experiment.…”

Section: Materials the Five Peptides ([Val4]-angiotensin IIIsupporting

confidence: 85%

Influence of the ratio of matrix to analyte on the fast atom bombardment mass spectrometric response of peptides sampled from aqueous glycerol

Ce¹,

Jf²,

Jt³

1989

Anal. Chem.

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Fast atom bombardment mass spectrometry (FAB-MS) studies of the nonapeptide bradykinin sampled from aqueous glycerol illustrate the importance of the matrix to analyte ratio in the FAB experiment. Enhanced mass spectral results (in conventional direct probe FAB analyses) are characterized by increased ionization efficiency of the analyte together with a substantial reduction in the glycerol background signal. Replicate analyses of different bradykinin/glycerol/water mixtures show this improvement to depend upon the glycerol/bradykinin relationship and not the water/bradykinin relationship in sampling 4 nmol of bradykinin from 1% to 56% aqueous glycerol (2 microL initial sample volumes). The optimum desorption ionization occurs when the molar ratio of glycerol to bradykinin is approximately 300:1. A model emphasizing the importance of the analyte surface concentration in the matrix (with water being simply a convenient vehicle for the deposition of minute portions of glycerol) is proposed to account for the spectral enhancement. The FAB-MS enhancement behavior of four other peptides, selected for their differences in hydrophobicity (and hence, surface activity in glycerol), is compared to that of bradykinin.

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Section: Materials the Five Peptides ([Val4]-angiotensin IIIsupporting

confidence: 85%

Influence of the ratio of matrix to analyte on the fast atom bombardment mass spectrometric response of peptides sampled from aqueous glycerol

Ce¹,

Jf²,

Jt³

1989

Anal. Chem.

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“…Our methodology enabled peptide identification in relatively crude extracts obtained from as few as 20 central nervous systems. Sensitivity was increased by introducing the peptides to the mass spectrometer by free flow in an aqueous methanolic solution, which considerably increases the signal-to-noise ratio (Caprioli and Fan, 1986).…”

Section: Lymnaeamentioning

confidence: 99%

Identification, Distribution and Physiological Activity of Three Novel Neuropeptides of Lymnaea: FLRlamide and pQFYRlamide Encoded by the FMRFamide Gene, and a Related Peptide

Santama

Wheeler

Skingsley

et al. 1995

Eur J of Neuroscience

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We are interested in analysing the detailed modulation of defined neuronal systems by multiple neuropeptides encoded in the FMRFamide locus of the snail Lymnaea. Cloning of the FMRFamide gene has predicted the existence of two novel peptides previously unknown from biochemical analysis, the pentapeptides EFLRlamide and QFYRlamide. These peptides may form part of a new family of peptides sharing the sequence motif -FXRlamide. In this paper we adopt a novel approach to first identify and characterize -FXRlamide-like peptides in extracts from the central nervous system of Lymnaea. By a combination of high-performance liquid chromatography (HPLC) and continuous-flow fast atom bombardment mass spectrometry, we identify three novel peptides: EFLRlamide, pQFYRlamide and pQFLRlamide. The first two are those predicted in exon II of the FMRFamide locus whereas the last is, interestingly, a product which cannot be derived from post-translational modification of the predicted peptides but must be encoded by as yet unidentified nucleotide sequences. A specific antibody raised to EFLRlamide, and immunoreactive to all three peptides, revealed EFLRlamide-like expression throughout the central nervous system in the same cells where exon II is transcribed and the peptide SEEPLY (a post-translational product of exon II) was localized. Additional cells, however, were also identified. Immunoreactivity was mapped in a number of identified neurons in the central nervous system, including two heart cardioexcitatory motoneurons, the Ehe cells (E heart excitors of the visceral ganglion) and penial motoneurons in the right cerebral ganglion. The peripheral tissues (heart and penial complex) that these respective classes of neurons innervate also exhibited EFLRlamide immunoreactivity. The central and peripheral localization of EFLRlamide-like immunoreactivity suggested that EFLRlamide/pQFYRlamide may have an important physiological role in both these peripheral systems as well as in the central nervous system. This was confirmed by physiological experiments that showed that EFLRlamide and pQFYRlamide inhibited many central neurons and in particular the Bgp neurons in the right parietal ganglion. EFLRlamide had complex biphasic effects on the frequency of heart-beat: an initial inhibitory response was followed by a long-lasting increase in the rate of beating. Taken together with earlier work, this study now completes the analysis and localization of the full set of post-translational products of the FMRFamide precursor in Lymnaea and supplies further evidence towards the characterization of the physiological systems which such peptides may modulate in concert.

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“…Recently, Ito et al (6) and Caprioli et al (7) introduced a refinement to FAB and L-SIMS which offers a number of potential advantages. Rather than external application of sample to the probe tip and reinsertion into the ion source, this approach, now known as continuous flow (or dynamic) FAB or L-SIMS, conveniently introduces the analyte into a continuous stream of mobile phase containing the low volatility, viscous matrix and applies it, via capillary tubing, directly to the surface of the probe tip in the ion source (6)(7)(8)(9)(10). This technique combines the convenience of direct liquid introduction characteristic of most chromatographic techniques with the power of FAB or L-SIMS ionization technique.…”

Section: Introductionmentioning

confidence: 99%

Quantitative analysis of low-molecular-weight polar compounds by continuous flow liquid secondary ion tandem mass spectrometry

Wang¹,

Shih²,

Markey³

et al. 1989

Anal. Chem.

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Quantitative analyses of low molecular weight (100-200) polar compounds [1-methyl-4-phenylpyridine (MPP+), 2-amino-3-(methylamino)propanoic acid (synonyms, beta-(methyl-amino)-L-alanine or BMAA), and tryptophan] were conducted on a triple-stage quadrupole mass spectrometer configured for continuous flow liquid secondary ion mass spectrometry ionization (CF L-SIMS). It is shown that quantification by CF L-SIMS at subnanogram sensitivity can be precise (correlation coefficients greater than 0.99), accurate, specific, and routine for compounds not measurable by static L-SIMS. Successful analyses, however, are strongly dependent upon the stability of the film formed by the mobile phase on the probe tip. In our system, film stability is affected by mobile phase composition and flow rate, ion source and probe tip temperature, probe-tip and capillary alignment, film thickness, and sample composition.

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High sensitivity mass spectrometric determination of peptides: Direct analysis of aqueous solutions

Cited by 56 publications

References 3 publications

Influence of the ratio of matrix to analyte on the fast atom bombardment mass spectrometric response of peptides sampled from aqueous glycerol

Influence of the ratio of matrix to analyte on the fast atom bombardment mass spectrometric response of peptides sampled from aqueous glycerol

Identification, Distribution and Physiological Activity of Three Novel Neuropeptides of Lymnaea: FLRlamide and pQFYRlamide Encoded by the FMRFamide Gene, and a Related Peptide

Quantitative analysis of low-molecular-weight polar compounds by continuous flow liquid secondary ion tandem mass spectrometry

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