Peptide sequence tag

Mann, M. (1996). A shortcut to interesting human genes peptide sequence tags, expressed-sequence tags and computers. Trends Biochem. Sci. 21, 494-495. 

Mann, M. Wilm, M. Error-tolerant identification of peptides in sequence databases by peptide sequence tags. Anal. Chem. 1994, 66,4390-4399. 

M. Mann and M. Wilm. Error-Tolerant Identification of Peptides in Sequence Databases by Peptide Sequence Tags. Anal. Chem., 66(1994) 4390-4399. 

This method can be improved further by using peptide sequence information obtained by MS/MS. Indeed, the sequence or even part of the sequence of a peptide is more specific than its molecular mass. This approach, termed peptide sequence tag, allows a protein to be identified from a partial sequence and from mass differences between this sequence and the N-terminal and the C-terminal of the peptide resulting from cleavage of the protein [87,88], There is a second approach widely used for protein identification that is closely related to PMF. This approach is also based on MS/MS but does not require the interpretation in terms of sequence of the observed fragments. The observed masses of fragment ions are compared with those expected for the various proteolytic peptides deduced from each... 

The second approach uses peptide sequence tags to identify the peptide, and therefore the protein. This method is based on the assumption that in a MS/MS peptide spectrum some consecutive amino acid residues can usually be clearly identified. In a typical protocol, the peptides obtained from a protein tryptic digest are... 

Peptide sequence tags with multidimensional protein identification technology 466... 

Other possibilities to improve the results of MS/MS data comparison are to combine this information with peptide sequence tags or the amino add composition. This information is taken into account in programs such as MS-Tag, MS-Seq, PepFrag [158] and PeptideSearch. 

It is also possible to combine on-line LC with ECD MS/MS. This approach was applied to the analysis of the protein Fc-ROR2 that was isolated from chondrocytes and digested with trypsin [113]. Analysis by LC ECD MS/MS cannot be undertaken in a parallel manner ECD must take place in the ICR cell. The previous survey scan must, therefore, be completed prior to ECD. Consequently, the duty cycle is reduced. A further disadvantage of this approach is the inherent inefficiency of ECD (see above). It is necessary to accumulate more precursor ions for ECD, with a concomitant increase in experiment time. The accumulation time is of the order of seconds rather than the milliseconds required for accumulation for CID. Nevertheless, studies have shown that ECD results in longer peptide sequence tags than does CID, thus improving confidence in peptide assignment [114]. Approaches which combine LC with ECD and CID have been developed also and are discussed further below [115-118]. 

Peptide sequence tags with MALDI-MS/MS. The gel-separated protein spots are digested as above and are deposited onto a large-format MALDI plate either directly or after separation by RP-HPLC. The matrix is added, and the spotted samples are analyzed with MALDI-MS/MS on a TOF/TOF tandem instrument [58]. MALDI-ion traps and MALDI-Q-TOF are also suitable for this purpose. 

Peptide sequence tags with multidimensional protein identification technology (MudPIT). MudPIT is a gel-free shotgun proteomic approach, which does... 

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