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US 12,618,849 B2Granted
Peptide analyzing method
AssigneeShimadzu Corporation
InventorRitsuko Yoda
Life of this patent
Estimating the term…
Abstract
In the analysis method according to the present invention, a predetermined peptide is separated by immunoprecipitation using an antibody which specifically binds to either an N-terminus or a C-terminus of the predetermined peptide. The separated predetermined peptide is digested with a protease to prepare peptide fragments, and among the peptide fragments, a peptide fragment at a terminus opposite to a terminus binding to the antibody is mass-spectrometrically detected.
Claims6
A peptide analyzing method comprising:
- separating Aβ1-42 from Aβ1-40 and APP669-711 by immunoprecipitation using an antibody which specifically binds to a C-terminus of Aβ1-42, or separating Aβ1-40 and APP669-711 from Aβ1-42 by immunoprecipitation using an antibody which specifically binds to a C-terminus of Aβ1-40 or APP669-711;
- preparing peptide fragments by digesting with a protease Aβ1-40 and APP669-711 separated;
- and
- mass-spectrometrically detecting, among the peptide fragments, a peptide fragment at the N-terminus of Aβ1-40 and APP669-711.
1 more element
A method for analyzing peptides, comprising:
- preparing a biological sample containing plural types of peptides produced by cleaving a precursor protein at different cleavage sites with in vivo processing, wherein the plural types of peptides are generated from an amyloid precursor protein (APP);
- contacting the biological sample with an antibody that specifically binds to a C-terminus of Aβ1-42;
- separating, by immunoprecipitation, peptides that are bound to the antibody from those that are not bound to the antibody, among the plural types of peptides;
- digesting the separated peptides with an enzyme to obtain peptide fragments;
- analyzing the obtained peptide fragments by mass spectrometry;
- and
- based on the results of the mass spectrometry, making the following determinations:
- I) determining that an ion derived from a peptide fragment that has a sequence at an N-terminus corresponding to an N-terminus side of Aβ1-40 detected in the mass spectrometry is an ion derived from peptide fragment generated from Aβ1-40 present in the biological sample by the enzyme digestion, rather than an ion derived from peptide fragments generated from Aβ1-42 present in the biological sample by the enzyme digestion;
- and II) determining that an ion derived from peptide fragments that has a sequence at an N-terminus corresponding to an N-terminus side of APP669-711 detected in the mass spectrometry is an ion derived from peptide fragment generated from APP669-711 present in the biological sample, generated by the enzyme digestion.
6 more elements
A method for analyzing peptides, comprising:
- preparing a biological sample containing plural types of peptides, wherein the plural types of peptides are generated from the amyloid precursor protein (APP) being cleaved at different sites due to in vivo processing;
- contacting the biological sample with an antibody that specifically binds to a C-terminus of Aβ1-40 or APP669-711;
- separating, by immunoprecipitation, peptides that are bound to the antibody from those that are not bound to the antibody, among the plural types of peptides;
- digesting the separated peptides with an enzyme to obtain peptide fragments;
- analyzing the obtained peptide fragments by mass spectrometry;
- and
- based on the results of the mass spectrometry, making the following determinations:
- I) determining that an ion derived from a peptide fragment that has a sequence at an N-terminus corresponding to an N-terminus side of Aβ1-40 detected in the mass spectrometry is an ion derived from a peptide fragment generated from Aβ1-40 present in the biological sample by the enzyme digestion, rather than an ion derived from peptide fragments generated from Aβ1-42 present in the biological sample by the enzyme digestion;
- and II) determining that an ion derived from peptide fragments that has a sequence at an N-terminus corresponding to an N-terminus side of APP669-711 detected in the mass spectrometry is an ion derived from a peptide fragment generated from APP669-711 present in the biological sample, generated by the enzyme digestion.
6 more elements
Dependencies are inferred from the claim text.