Identification of microbial mixtures by LC-selective proteotypic-peptide analysis(SPA)

Recent work has shown that DNA sequences related to the mammalian ras proto-oncogenes are highly conserved in eucaryotic evolution. A monoclonal antibody (Y13-259) to mammalian p21ras specifically precipitated a 23,000-molecular-weight protein (p23) from lysates of Dictyostelium discoideum amoebae. Tryptic peptide analysis indicated that D. discoideum p23 was closely related in its primary structure to mammalian p21ras. p23 was apparently derived by post-translational modification of a 24,000-molecular-weight primary gene product. The amount of p23 was highest in growing amoebae, but declined markedly with the onset of differentiation such that by fruiting body formation there was less than 10% of the amoeboid level. The rate of p23 synthesis dropped rapidly during aggregation, rose transiently during pseudoplasmodial formation, and then declined during the terminal stages of differentiation. There was, therefore, a strong correlation between the expression of the ras-related protein p23 and cell proliferation of D. discoideum.

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MALDI-LID-ToF/ToF analysis of statistical and diblock polyacrylate copolymers

Polymer Chemistry ◽

10.1039/c8py00928g ◽

2018 ◽

Vol 9 (37) ◽

pp. 4631-4641 ◽

Cited By ~ 11

Author(s):

James S. Town ◽

Glen R. Jones ◽

David M. Haddleton

Keyword(s):

Peptide Analysis

We report the use of MALDI-LID-ToF/ToF utilising the laser induced dissociation (LID) fragmentation technique, which has been almost exclusively applied to protein/peptide analysis to date.

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Quantification of a Proteotypic Peptide from Protein C Inhibitor by Liquid Chromatography–Free SISCAPA-MALDI Mass Spectrometry: Application to Identification of Recurrence of Prostate Cancer

Clinical Chemistry ◽

10.1373/clinchem.2012.199786 ◽

2013 ◽

Vol 59 (10) ◽

pp. 1514-1522 ◽

Cited By ~ 40

Author(s):

Morteza Razavi ◽

Lisa DS Johnson ◽

Julian J Lum ◽

Gary Kruppa ◽

N Leigh Anderson ◽

...

Keyword(s):

Prostate Cancer ◽

Liquid Chromatography ◽

High Throughput ◽

Protein C ◽

Specific Antigen ◽

Serum Concentrations ◽

Serum Samples ◽

Biomarker Validation ◽

Protein C Inhibitor ◽

Proteotypic Peptide

BACKGROUND Biomarker validation remains one of the most challenging constraints to the development of new diagnostic assays. To facilitate biomarker validation, we previously developed a chromatography-free stable isotope standards and capture by antipeptide antibodies (SISCAPA)-MALDI assay allowing rapid, high-throughput quantification of protein analytes in large sample sets. Here we applied this assay to the measurement of a surrogate proteotypic peptide from protein C inhibitor (PCI) in sera from patients with prostate cancer. METHODS A 2-plex SISCAPA-MALDI assay for quantification of proteotypic peptides from PCI and soluble transferrin receptor (sTfR) was used to measure these peptides in 159 trypsin-digested sera collected from 51 patients with prostate cancer. These patients had been treated with radiation with or without neoadjuvant androgen deprivation. RESULTS Patients who experienced biochemical recurrence of prostate cancer showed decreased serum concentrations of the PCI peptide analyte within 18 months of treatment. The PCI peptide concentrations remained increased in the sera of patients who did not experience cancer recurrence. Prostate-specific antigen concentrations had no predictive value during the same time period. CONCLUSIONS The high-throughput, liquid chromatography–free SISCAPA-MALDI assay is capable of rapid quantification of proteotypic PCI and sTfR peptide analytes in complex serum samples. Decreased serum concentrations of the PCI peptide were found to be related to recurrence of prostate cancer in patients treated with radiation with or without hormone therapy. However, a larger cohort of patients will be required for unequivocal validation of the PCI peptide as a biomarker for clinical use.

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Protein and Peptide Analysis by Matrix-Assisted Laser Desorption/Ionization Tandem Mass Spectrometry (MALDI MS/MS)

Spectral Techniques In Proteomics ◽

10.1201/9781420017090-13 ◽

2007 ◽

pp. 89-102

Keyword(s):

Mass Spectrometry ◽

Tandem Mass Spectrometry ◽

Laser Desorption ◽

Tandem Mass ◽

Laser Desorption Ionization ◽

Peptide Analysis ◽

Desorption Ionization ◽

Ionization Tandem Mass Spectrometry ◽

Matrix Assisted Laser ◽

Matrix Assisted Laser Desorption

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Changes in flavor compounds of Aloididae aloidi during enzymatic hydrolysis

E3S Web of Conferences ◽

10.1051/e3sconf/202123302040 ◽

2021 ◽

Vol 233 ◽

pp. 02040

Author(s):

Xuting Bai ◽

Tao Li ◽

Honglei Zhao ◽

Xuepeng Li ◽

Wenhui Zhu ◽

...

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Enzymatic Hydrolysis ◽

Free Amino Acid ◽

Free Amino Acids ◽

Free Amino ◽

Flavor Compounds ◽

Peptide Analysis ◽

Soluble Peptide ◽

Maximum Value

Protamex was selected to prepare the hydrolysate. E-tongue, free amino acid combined with soluble peptide analysis were used to detect the flavor changes of Aloididae aloidi during enzymolysis. Degree of proteolysis increased with the prolongation of enzymolysis time, and reached the maximum value at 8 hours. The content of soluble peptide of hydrolysate increased firstly and then decreased in the later process. The E-tongue could effectively distinguish the taste difference of hydrolysates at different enzymolysis time, and the hydrolysate presented strong bitterness and astringency during the whole enzymolysis. The total amount of free amino acids in the hydrolysate increased gradually, and some sweet, umami and bitter amino acids increased in varying degrees during the process of enzymolysis.

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Solid-state 17O NMR Study of Small Biological Compounds

Zeitschrift für Naturforschung B ◽

10.1515/znb-2007-1111 ◽

2007 ◽

Vol 62 (11) ◽

pp. 1422-1432 ◽

Cited By ~ 8

Author(s):

Kazuhiko Yamada ◽

Tadashi Shimizu ◽

Yoshida Mitsuru ◽

Miwako Asanuma ◽

Masataka Tansho ◽

...

Keyword(s):

Solid State ◽

Magic Angle Spinning ◽

Magic Angle ◽

Multiple Quantum ◽

Peptide Analysis ◽

17O Nmr ◽

Nmr Study ◽

Biological Compounds ◽

Nmr Tensors ◽

Angle Spinning

We present a systematic experimental and theoretical investigation of the oxygen chemical shielding and electric-field-gradient tensors in polycrystalline amino acids and a peptide. Analysis of the 17O magic-angle-spinning (MAS), multiple-quantum MAS, and stationary nuclear magnetic resonance (NMR) spectra yield the magnitudes and the relative orientations between the two NMR tensors. The obtained 17O NMR parameters are sensitive to the hydrogen bond environments. We also demonstrate that solid-state 17O NMR is potentially useful for studying the secondary structures of peptides and proteins.

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