摘要:
The present invention provides an instrument and methods for the preparative separation of components of mixtures using mass spectrometric methods. Nondestructive ionization methods are employed to generate ionized components of a mixture, the ionized components are spatially separated by mass and the mass-separated ion components are trapped. The ion source and mass spectrometric techniques employed allow the generation of large ion currents of ion components, on the order of nanoamps, which facilitate rapid accumulation of nanomole quantities of mass-separated components in relatively short times (minutes to hours).
摘要:
Method and reagent for converting a carboxylic acid to a positively charged amide. The method and reagent facilitate positive ion mass spectral analysis of carboxylic acids.
摘要:
Analytical reagents and mass spectrometry-based methods using these reagents for the rapid, and quantitative analysis of proteins or protein function in mixtures of proteins. The methods employ affinity labeled protein reactive reagents having three portions: an affinity label (A) covalently linked to a protein reactive group (PRG) through a linker group (L). The linker may be differentially isotopically labeled, e.g., by substitution of one or more atoms in the linker with a stable isotope thereof. These reagents allow for the selective isolation of peptide fragments or the products of reaction with a given protein (e.g., products of enzymatic reaction) from complex mixtures. The isolated peptide fragments or reaction products are characteristic of the presence of a protein or the presence of a protein function in those mixtures. Isolated peptides or reaction products are characterized by mass spectrometric (MS) techniques. The reagents also provide for differential isotopic labeling of the isolated peptides or reaction products which facilitates quantitative determination by mass spectrometry of the relative amounts of proteins in different samples. The methods of this invention can be used for qualitative and quantitative analysis of global protein expression profiles in cells and tissues, to screen for and identify proteins whose expression level in cells, tissue or biological fluids is affected by a stimulus or by a change in condition or cell state of the cell, tissue or organism from which the sample originated.
摘要:
Method and reagent for converting a carboxylic acid to a positively charge amide are described. The method and reagent facilitate positive ion mass spectral analysis of carboxylic acids. The method includes reacting a carboxylic acid with a compound having formula I: wherein A and B are aromatic rings, ring A includes a quaternized nitrogen and has n additional ring atoms, each additional ring atom optionally substituted with an RA group, and n is an integer from 4 to 10, and ring B includes a carbon atom and has m additional ring atoms, each additional ring atom optionally substituted with an RB group, and m is an integer from 4 to 10. The compound includes at least one RA or RB group, and the at least one RA and RB group is -L-N(Z)H; and X− is a counterion.
摘要:
Analytical reagents and mass spectrometry-based methods using these reagents for the rapid, and quantitative analysis of proteins or protein function in mixtures of proteins. The methods employ affinity labeled protein reactive reagents having three portions: an affinity label (A) covalently linked to a protein reactive group (PRG) through a linker group (L). The linker may be differentially isotopically labeled, e.g., by substitution of one or more atoms in the linker with a stable isotope thereof. These reagents allow for the selective isolation of peptide fragments or the products of reaction with a given protein (e.g., products of enzymatic reaction) from complex mixtures. The isolated peptide fragments or reaction products are characteristic of the presence of a protein or the presence of a protein function in those mixtures. Isolated peptides or reaction products are characterized by mass spectrometric (MS) techniques. The reagents also provide for differential isotopic labeling of the isolated peptides or reaction products which facilitates quantitative determination by mass spectrometry of the relative amounts of proteins in different samples. The methods of this invention can be used for qualitative and quantitative analysis of global protein expression profiles in cells and tissues, to screen for and identify proteins whose expression level in cells, tissue or biological fluids is affected by a stimulus or by a change in condition or state of the cell, tissue or organism from which the sample originated.
摘要:
The invention provides a reagent comprising an affinity tag, a detectable moiety, a linker, an isotope tag and a reactive group. The invention also provides methods of using a reagent of the invention. The methods can be used to label a polypeptide in a sample by contacting a sample with a reagent of the invention under conditions allowing the reactive group to bind to one or more polypeptides in the sample. The invention additionally provides methods of isolating, identifying and quantifying a polypeptide in a sample. The invention further provides methods of diagnosing a disease using a reagent of the invention.
摘要:
Analytical reagents and mass spectrometry-based methods using these reagents for the rapid, and quantitative analysis of proteins or protein function in mixtures of proteins. The methods employ affinity labeled protein reactive reagents having three portions: an affinity label (A) covalently linked to a protein reactive group (PRG) through a linker group (L). The linker may be differentially isotopically labeled, e.g., by substitution of one or more atoms in the linker with a stable isotope thereof. These reagents allow for the selective isolation of peptide fragments or the products of reaction with a given protein (e.g., products of enzymatic reaction) from complex mixtures. The isolated peptide fragments or reaction products are characteristic of the presence of a protein or the presence of a protein function in those mixtures. Isolated peptides or reaction products are characterized by mass spectrometric (MS) techniques. The reagents also provide for differential isotopic labeling of the isolated peptides or reaction products which facilitates quantitative determination by mass spectrometry of the relative amounts of proteins in different samples. The methods of this invention can be used for qualitative and quantitative analysis of global protein expression profiles in cells and tissues, to screen for and identify proteins whose expression level in cells, tissue or biological fluids is affected by a stimulus or by a change in condition or state of the cell, tissue or organism from which the sample originated.
摘要:
The invention provides a reagent comprising an affinity tag, a detectable moiety, a linker, an isotope tag and a reactive group. The invention also provides methods of using a reagent of the invention. The methods can be used to label a polypeptide in a sample by contacting a sample with a reagent of the invention under conditions allowing the reactive group to bind to one or more polypeptides in the sample. The invention additionally provides methods of isolating, identifying and quantifying a polypeptide in a sample. The invention further provides methods of diagnosing a disease using a reagent of the invention.
摘要:
Analytical reagents and mass spectrometry-based methods using these reagents for the rapid, and quantitative analysis of proteins or protein function in mixtures of proteins. The methods employ affinity labeled protein reactive reagents having three portions: an affinity label (A) covalently linked to a protein reactive group (PRG) through a linker group (L). The linker may be differentially isotopically labeled, e.g., by substitution of one or more atoms in the linker with a stable isotope thereof. These reagents allow for the selective isolation of peptide fragments or the products of reaction with a given protein (e.g., products of enzymatic reaction) from complex mixtures. The isolated peptide fragments or reaction products are characteristic of the presence of a protein or the presence of a protein function in those mixtures. Isolated peptides or reaction products are characterized by mass spectrometric (MS) techniques. The reagents also provide for differential isotopic labeling of the isolated peptides or reaction products which facilitates quantitative determination by mass spectrometry of the relative amounts of proteins in different samples. The methods of this invention can be used for qualitative and quantitative analysis of global protein expression profiles in cells and tissues, to screen for and identify proteins whose expression level in cells, tissue or biological fluids is affected by a stimulus or by a change in condition or state of the cell, tissue or organism from which the sample originated.