Peptide fingerprint

Qnadroni, M., et al., 1996. Analy.sis of global re.spon.ses by protein and peptide fingerprinting of protein.s i.solated by two-dimensional electrophore-.sis. Application to snlfate-starvation re.sponse of Escherichia coli. European Journal of Biochemistry 239 773-781. This paper de.scribes the n.se of tandem MS in the analysis of protein.s in cell extracts. 

Chambery, A., del Monaco, G., Di Maro, A., and Parente, A. (2009). Peptide fingerprint of high quality Campania white wines by MALDl-TOP mass spectrometry. Food Chem. 113, 1283-1289. 

Figure 2.4. Peptide fingerprinting by MALDI-TOF mass Spectrometry. Proteins are extracted and separated on by 2D gel electrophoresis. A spot of interest is excised from the gel, digested with trypsin, and ionized by MALDI. The precise mass of proteolytic fragments is determined by time-of- flight mass spectrometry. The identity of the protein is determined by comparing the peptide masses with a list of peptide masses generated by a simulated digestion of all of the open reading frames of the organism.

The major advantage of the tandem mass spectrometry approach compared to MALDI peptide fingerprinting, is that the sequence information obtained from the peptides is more specific for the identification of a protein than simply determining the mass of the peptides. This permits a search of expressed sequence tag nucleotide databases to discover new human genes based upon identification of the protein. This is a useful approach because, by definition, the genes identified actually express a protein. 

Bemdt, P., Hobohm, U., and Langen, H. (1999). Reliable automatic protein identification from matrix-assisted laser desorption/ionization mass spectrometric peptide fingerprints. Electrophoresis 20, 3521-3526. 

Tryptic peptide fingerprint studies (44) of the pure isozymes I and III showed a ninhydrin-positive peptide in isozyme I that is missing in isozyme III and two weakly ninhydrin-positive spots present in isozyme III but not in isozyme I. The two peptides sequences present only in isozyme III are more negatively charged than the one present in isozyme I. Since there are 36 tryptic peptides, it appears that the structural differences between the isozymes are not extensive. 

Finally, the goal of this first phase is to analyze and to compare the resulting proteins and peptides by alignment search tools, such as BLAST (http / blast.ncbi.nlm.nih.gov/Blast.cgi CMD=Web PAGE TYPE=BlastHome), in order to identify and characterize specific peptide fingerprints, which will be used in the monitoring approach of the next phase of the pipeline. 

Add0.5-1 iL matrix and ensure that crystals are formed that cover the entire sample well. Submit samples for analysis by mass spectrometry and compare peptide fingerprint with theoretic peptide masses in online databases (see Note 8). 

MALDI-TOF Requires high resolution mass spectrometry for protein identification based on peptide fingerprinting. Analytical... 

Figure 3 A general outline of proteomics approach for profiling proteins (a) peptide fingerprinting-based proteomics, (b) sequence ion-based proteomics. Reproduced from C. Dass, Principles and Practice of Biological Mass Spectrometry Wiley-lnterscience Hoboken, NJ, 2000, with permission from Wiley-Interscience, Copyright 2001.

One of the strengths of this technique is the ability to identify posttranslationally modified proteins by following a change in mass. In this study, the authors reported a change in the proportion of a-N-acetylated (m/z 17,882) and nonacetylated (m/z 17,840) cyclophilin A (Cyp A) between the normal prostate and prostate tumors. (The identity of Cyp A was confirmed by HPLC separation, MALDI MS peptide fingerprinting, and MS/MS analysis). These results were confirmed by Western blotting and immunohistochemical analyses [37],... 

Ricin and RCA are closely related proteins. It has been established for some time that antisera raised against individual ricin A or B chains cross-react with the corresponding RCA chains and vice versa [16-18], Peptide fingerprinting... 

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