Introduction for Sequence Analysis of Peptides or proteins

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Introduction for Sequence Analysis of Peptides or
proteins

• Summary Creative Proteomis provides N-terminal
  sequence analysis by both Edman and Mass
  spectrometry of therapeutic proteins, monoclonal
  antibodies and protein vaccines. In this article,
  we mainly introduce the function of N-terminal in
  the sequence analysis of peptides or proteins.

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• Body Protein sequence analysis has been the
  meaningful and challenging work in the protein
  chemistry. And N-terminal Edman sequencing has
  the advantage, which never can be gained by other
  methods, for the protein analysis. 80 soluble
  protein in eukaryotic cells, its N-terminal NH2
  groups are blocked because of the translational
  modification. So it is very difficult to
  degradate the Edman. Additionally, the separation
  process is also a cause for the whole close of
  amino acid. Therefore, only by removing these
  groups or cutting off the protein inside, then
  with the peptides from the mixture, can analysis
  of amino acid be got. In N-terminal analysis,
  after modification with phenylisothiocyanate(PITC)
  , the derivatized terminal amino acid is removed
  by acid cleavage as its phenylthiohydantoin(PTH)
  derivative and a new amino group on the next
  amino acid is now available to react with PITC.
  The series of sequencer reactions results in
  ifentification of the N-terminal amino acid
  present on the peptide pr protein at the begining
  of that cycle. If each step were 100 efficient,
  it would be possible to sequence an entire
  protein in a single sequencer run, while in
  practice multiple factors limit the amount of
  sequence information that can be obtained. With
  current technology, it is fairly routine to
  obtain at least 20 to 25 residues of sequence
  from the N-terminus of the proteins and peptides.

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• Currently, the most common applications for
  protein sequence analysis are as follows.
  Verification of the N-terminal boundary of
  recombinant proteins, particularly proteins which
  is larger than 40-80 kDa when highly accurate
  masses cannot be obtained by ESI-MS. Determining
  the N-terminal boundary of protease-resistant
  domains, particularly when the protein or domain
  is greater than 40-80 kDa or when the domain of
  interest can not be readily purified. Identifying
  proteins isolated from species where most of the
  genome has not yet been sequenced. In rhre
  increasingly rare cases where the target protein
  is not in availabledatabases, the peptide
  sequence may be used either to design
  oligomicleotide probes or to confirm putative
  cDNA clones. Besides, sequence analysis of
  proteins can be used to identify modification
  residues or crosslinked sites in proteins that
  prove to be refractory to analysis by mass
  spectrometry.

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• About the author Creative Proteomics is the
  proteomics division of CD Inc, and integrated CRO
  company. And it offers a full range of drug
  development services. We are staffed by
  scientists who are very experienced in
  hard-to-analysis samples. Our services contain a
  thorough discussion and counseling of your
  projects, to offer you optimal service you
  demand. In close cooperation with our partners,
  professional proteomcis solutions are provided at
  the lowest cost level in the industry.
• Links http//www.creative-proteomics.com/Services
  /Sequence-analysis-of-peptides-or-proteins-NC.htm
• http//www.creative-proteomcis.com