Biomaterial Database

C-terminal peptide sequencing using acetylated peptides with MSn in a quadrupole ion trap. 2000

A H Payne, and J H Chelf, and G L Glish

Department of Chemistry, University of North Carolina at Chapel Hill 27599-3290, USA.

MS/MS has been used to sequence peptides and small proteins for a number of years. This method allows one to isolate the peptide of interest, which makes it possible to analyze impure samples and unseparated mixtures, such as protein digests. Collision-induced dissociation (CID) of the selected peptide ion generates the product ions that provide sequence information. However, often the MS/MS spectrum does not provide adequate information for complete sequence determination. The quadrupole ion trap has the capability to do multiple stages of mass spectrometry, MSn, which can increase the information available to determine the peptide sequence. A regular and predictable dissociation pattern for peptides further simplifies this analysis. By forming predominantly one type of ion, ambiguity is removed as to whether the ion is N- or C-terminal. This pattern can also be advantageous in that ion intensity remains concentrated for the next stage of MS/MS. In this work, a method to take advantage of the MSn capabilities of the quadrupole ion trap by controlling the dissociation pathways is explored. Dissociation is altered by acetylating the N-terminus of the peptide. MSn of a variety of acetylated peptides is used to determine the effects of the identity of the C-terminal residue and the length of the peptide on the dissociation pathways observed.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D003574	Cytochrome c Group	A group of cytochromes with covalent thioether linkages between either or both of the vinyl side chains of protoheme and the protein. (Enzyme Nomenclature, 1992, p539)	Cytochromes Type c,Group, Cytochrome c,Type c, Cytochromes
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D013058	Mass Spectrometry	An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.	Mass Spectroscopy,Spectrometry, Mass,Spectroscopy, Mass,Spectrum Analysis, Mass,Analysis, Mass Spectrum,Mass Spectrum Analysis,Analyses, Mass Spectrum,Mass Spectrum Analyses,Spectrum Analyses, Mass