摘要:
Provided is a set of two or more mass labels, each label in the set comprising a mass marker moiety attached via a cleavable linker having at least one amide bond to a mass normalisation moiety, wherein the aggregate mass of each label in the set may be the same or different and the mass of the mass marker moiety of each label in the set may be the same or different, and wherein in any group of labels within the set having a mass marker moiety of a common mass each label has an aggregate mass different from all other labels in that group, and wherein in any group of labels within the set having a common aggregate mass each label has a mass marker moiety having a mass different from that of all other mass marker moieties in that group, such that all of the mass labels in the set are distinguishable from each other by mass spectromety, and wherein the mass marker moiety comprises an amino acid and the mass normalisation moiety comprises an amino acid.
摘要:
Provided is a method for characterising a polypeptide or a population of polypeptides, which method comprises the steps of:
(a) contacting a sample comprising one or more polypeptides with a lysine reactive agent to cap ε-amino groups; (b) optionally reacting the sample of polypeptides with an amine reactive reagent to block α-amino groups; (c) digesting the sample of polypeptides with a sequence specific cleavage reagent to produce peptide fragments; (d) optionally deactivating the cleavage reagent; (e) removing those peptides having uncapped or unblocked amino groups; and (f) recovering the N-terminal peptides.
摘要:
A method for characterising polypeptides, which comprises: (a) treating a sample comprising a population of one or more polypeptides with a cleavage agent which is known to recognise in polypeptide chains a specific amino acid residue or sequence and to cleave at a cleavage site, whereby the population is cleaved to generate peptide fragments; (b) isolating a population of the peptide fragments which bear at one end a reference terminus comprising either only an C-terminus or only an N-terminus and which bear at the other end the cleavage site proximal to the reference terminus; and (c) determining a signature sequence of at least some of the isolated framents, which signature sequence is the sequence of a predetermined number of amino acid residues running from the cleavage site; wherein the signature sequence and the relative position of the cleavage site to the reference terminus characterise the or each polypeptide.
摘要:
Provided is a method for characterising a polypeptide or a population of polypeptides, which method comprises the steps of:
(a) Optionally reducing disulphide linkages in the polypeptides, if they are present, and capping free thiols in the polypeptides, if they are present; (b) contacting a sample comprising one or more polypeptides with a sequence specific cleavage reagent which cleaves one or more polypeptides on the C-terminal side of a lysine residue to produce peptide fragments; (c) optionally deactivating the cleavage reagent; (d) contacting the sample with a lysine reactive agent to cap ε-amino groups; (e) removing those peptides having capped ε-amino groups; and (f) recovering the C-terminal peptides
摘要:
Provided is a method for characterising one or more nucleic acids, which method comprises immobilising double-stranded nucleic acids on a solid phase support, cleaving the immobilised nucleic acids with an endonuclease such that each cleaved nucleic acid has a double-stranded portion, denaturing the cleaved nucleic acids to form single-stranded cleaved nucleic acid, hybridising one or more oligonucleotide sequences to the resulting single-stranded cleaved nucleic acid, each oligonucleotide sequence comprising a pre-determined recognition sequence situated such that it recognises a sequence which was part of the double-stranded portion of the nucleic acid and a label specific to the recognition sequence, extending correctly hybridised oligonucleotide sequences along the single-stranded portion of the immobilised nucleic acid to form an extended strand, denaturing the extended strand from the immobilised strand and characterising the immobilised nucleic acid by identifying the size of the extended strand and the identity of the recognition sequence.
摘要:
Provided is a method for characterising a polypeptide, which method comprises the steps of: (a) optionnally reducing cysteine disulphide bridges in the polypeptide to form free thiols, and capping the free thiols; (b) cleaving the polypeptide with a sequence specific cleavage reagent to form peptide fragments; (c) optionally deactivating the cleavage reagent; (d) capping one or more ε-amino groups that are present with a lysine reactive agent; (e) analysing peptide fragments by mass spectrometry to form a mass fingerprint for the polypeptide; and (f) determining the identity of the polypeptide from the mass fingerprint.
摘要:
Provided is a method for characterising a polypeptide or a population of polypeptides, which method comprises the steps of: (a) contacting a sample comprising one or more polypeptides with a lysine reactive agent to cap ε-amino groups; (b) optionally reacting the sample of polypeptides with an amine reactive reagent to block α-amino groups; (c) digesting the sample of polypeptides with a cleavage reagent to produce peptide fragments; (d) optionally deactivating the cleavage reagent; (e) removing those peptides having uncapped or unblocked amino groups; and (f) recovering the N-terminal peptides.
摘要:
The invention relates to peptidic domains, which are made available in a slightly synthetic manner, and which can specifically identify and bind nucleic acid sequences. The invention also relates to a method for discovering and providing specifically DNA-binding peptide domains, and to biomorph factors derived therefrom, in particular, transcription factors and repressors.
摘要:
Provided is a method for characterising a polypeptide or a population of polypeptides, which method comprises: (a) contacting a sample comprising one or more polypeptides with a first cleavage agent to generate polypeptide fragments; (b) isolating one or more polypeptides fragments, each fragment comprising the N-terminus or the C-terminus of the polypeptide from which it was fragmented; (c) identifying the isolated fragments by mass spectrometry; (d) repeating steps (a)-(c) on the sample using a second cleavage agent that cleaves at a different site from the first cleavage agent; and (e) characterising the one or more polypeptides in the sample from the fragments identified in steps (c) and (d).
摘要:
Provided is a method for characterising a molecule by mass spectrometry, which molecule comprises one or more free amino groups, which method comprises: (a) reacting one or more free amino groups in the molecule with a mass tag reagent comprising a reactive functionality capable of reacting with an amino group, and a tertiary amino group linked to the reactive functionality; and (b) characterising the molecule by mass spectrometry.