Unequivocal Identification of Aspartic Acid and isoAspartic Acid by MALDI-TOF/TOF: From Peptide Standards to a Therapeutic Antibody

2021 ◽  
Author(s):  
John O. Hui ◽  
Tawnya Flick ◽  
Joseph A. Loo ◽  
Iain D. G. Campuzano
Keyword(s):  
Aspartic Acid ◽  
Therapeutic Antibody ◽  
Isoaspartic Acid ◽  
Maldi Tof ◽  
Unequivocal Identification

scholarly journals Top-down proteomic identification of plasmid and host proteins produced by pathogenic Escherichia coli using MALDI-TOF-TOF tandem mass spectrometry

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260650
Author(s):  
Clifton K. Fagerquist ◽  
Claire E. Dodd
Keyword(s):  
Mass Spectrometry ◽  
Escherichia Coli ◽  
Tandem Mass Spectrometry ◽  
Aspartic Acid ◽  
Protein Sequences ◽  
Tandem Mass ◽  
Host Proteins ◽  
Top Down ◽  
Maldi Tof ◽  
Fragment Ions

Fourteen proteins produced by three pathogenic Escherichia coli strains were identified using antibiotic induction, MALDI-TOF-TOF tandem mass spectrometry (MS/MS) and top-down proteomic analysis using software developed in-house. Host proteins as well as plasmid proteins were identified. Mature, intact protein ions were fragmented by post-source decay (PSD), and prominent fragment ions resulted from the aspartic acid effect fragmentation mechanism wherein polypeptide backbone cleavage (PBC) occurs on the C-terminal side of aspartic acid (D), glutamic acid (E) and asparagine (N) residues. These highly specific MS/MS-PSD fragment ions were compared to b- and y-type fragment ions on the C-terminal side of D-, E- and N-residues of in silico protein sequences derived from whole genome sequencing. Nine proteins were found to be post-translationally modified with either removal of an N-terminal methionine or a signal peptide. The protein sequence truncation algorithm of our software correctly identified all full and truncated protein sequences. Truncated sequences were compared to those predicted by SignalP. Nearly complete concurrence was obtained except for one protein where SignalP mis-identified the cleavage site by one residue. Two proteins had intramolecular disulfide bonds that were inferred by the absence of PBC on the C-terminal side of a D-residue located within the disulfide loop. These results demonstrate the utility of MALDI-TOF-TOF for identification of full and truncated bacterial proteins.

scholarly journals Deamidation of Asparagine in a Major Histocompatibility Complex–Bound Peptide Affects T Cell Recognition but Does Not Explain Type B Reactivity

2001 ◽  
Vol 194 (8) ◽  
pp. 1165-1170 ◽  
Author(s):  
Thomas P. Cirrito ◽  
Zheng Pu ◽  
M. Brian Deck ◽  
Emil R. Unanue
Keyword(s):  
T Cells ◽  
T Cell ◽  
Aspartic Acid ◽  
Cell Receptor ◽  
Type B ◽  
Isoaspartic Acid ◽  
Egg White Lysozyme ◽  
Asparagine Deamidation ◽  
Hen Egg White ◽  
Dominant Epitope

We have analyzed a panel of T cell hybridomas specific for the chemically dominant epitope of hen egg-white lysozyme 48–61 which has asparagine 59 as an important T cell receptor contact residue. A number of T cells recognize 48–61 with asparagine at position 59, but not the aspartic acid or isoaspartic acid derivatives. Conversely, we find T cells that specifically recognize 48–61 bearing an isoaspartic acid at residue 59, but not asparagine. For other T cells, asparagine, aspartic acid, or isoaspartic acid at residue 59 is irrelevant. We present evidence that our previous distinction between type A and type B T cells is not explained by asparagine deamidation at residue 59.

Development of a Rapid Survey Method of Sampling and Analysis for Asbestos in Ambient Air

1972 ◽  
Vol 30 ◽  
pp. 630-631 ◽  
Author(s):  
R. E. Heffelfinger ◽  
C. W. Melton ◽  
D. L. Kiefer ◽  
W. M. Henry ◽  
R. J. Thompson
Keyword(s):  
Neutron Activation ◽  
Ambient Air ◽  
Survey Method ◽  
Potential Hazard ◽  
Transmission Microscopy ◽  
Comparative Analyses ◽  
Asbestos Fibers ◽  
Controlled Conditions ◽  
Unequivocal Identification ◽  
Identification And Quantification

A methodology has been developed and demonstrated which is capable of determining total amounts of asbestos fibers and fibrils in air ranging from as low as fractional nanograms per cubic meter (ng/m3) of air to several micrograms/m3. The method involves the collection of samples on an absolute filter and provides an unequivocal identification and quantification of the total asbestos contents including fibrils in the collected samples.The developed method depends on the trituration under controlled conditions to reduce the fibers to fibrils, separation of the asbestos fibrils from other collected air particulates (beneficiation), and the use of transmission microscopy for identification and quantification. Its validity has been tested by comparative analyses by neutron activation techniques. It can supply the data needed to set emissions criteria and to serve as a basis for assessing the potential hazard for asbestos pollution to the populace.

895: Proteomic Analysis of Sera from Bladder Cancer Patients with MALDI-TOF-MS

2007 ◽  
Vol 177 (4S) ◽  
pp. 297-297
Author(s):  
Kristina Schwamborn ◽  
Rene Krieg ◽  
Ruth Knüchel-Clarke ◽  
Joachim Grosse ◽  
Gerhard Jakse
Keyword(s):  
Bladder Cancer ◽  
Cancer Patients ◽  
Proteomic Analysis ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

MALDI TOF Massenspektrometrie zur Diagnostik der Präeklampsie und der Vergleich mit den Serummarkern PlGF, sFlt1 und Endoglin

2008 ◽  
Vol 68 (S 01) ◽  
Author(s):  
U Pecks ◽  
R Krieg ◽  
C Bartz ◽  
H Stepan ◽  
W Rath
Keyword(s):  
Maldi Tof

HPTLC-MALDI/TOF/MS vs. HPLC-ESI/MS2 for identification to flavonoids in plant extracts

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
L Fougère ◽  
D Da Silva ◽  
E Destandau ◽  
C Elfakir
Keyword(s):  
Plant Extracts ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

Infektionserreger beim Schwein – Analyse des kultivierbaren Mikrobioms mittels MALDI-TOF MS

2017 ◽  
Author(s):  
M Erhard ◽  
M Metzner ◽  
D Köhler-Repp ◽  
B Köhler ◽  
R Storandt
Keyword(s):  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

Quantitative metabolomics of Iranian saffron based on their HPLC-DAD and MALDI-TOF-MS

2019 ◽  
Author(s):  
M Hooshyari ◽  
H Rezadoost ◽  
P Ghezellou ◽  
A Ghassempour
Keyword(s):  
Maldi Tof Ms ◽  
Quantitative Metabolomics ◽  
Maldi Tof ◽  
Tof Ms
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