Introduction for the Peptide Mass Fingerprint(PMF)

Tags: Peptide Mass Fingerprint, Creative Proteomcis
Introduction for the Peptide Mass Fingerprint(PMF)
Summary: Peptide mass fingerprint (PMF), for protein identification, is an analytical technique. And Creative Proteomics offers Pepide mass fingerprinting (PMF) analysis and ions searching against database for rapid identification of proteins. In this article, we will introduce the Peptide mass fingerprinting, and mainly about its function and the theory it works.
Body: basically, the unknown protein of interest is cut into smaller peptides firstly, and the smaller peptides’ absolute masses can be accurately measured with a mass spectrometer, just like the MALDI-TOF or ESI-TOF. After that, the masses are compared to either a database, which includes known protein sequences or even the genome sequence which can be translated into proteins through computer programs. Then the absolute masses of the peptides, which is from each protein, are calculated theoretically for mass comparison between the peptides of the unknown protein and the theoretical peptide masses of each protein to find the best match.
The advantage of PMF method is that only the masses of the peptides is need to be known, while time-consuming de novo peptide sequencing id then unnecessary, it will not be used until the protein sequence is present in the database of interest. In spite of that, most PMF algorithms assume that the peptides which comes from a single protein while the presence of a mixture can significantly complicate the analysis and potentially compromise the results, thus an isolated protein is needed for the PMF based protein identification. Mixture exceeding a number of 2-3 proteins typically require the additional use of MS/MS based protein identification to achieve sufficient specificity of identification.
In sample preparation for PMF, protein sample can be generated from SDS-PAGE and then subject to some chemical modifications. Disulfide bridges in proteins are reduced and cysteine amino acids are carbamidomethylated chemically or acrylamidated during the gel electrophoresis. Then the then the proteins are derived into several fragments with the proteolytic enzymes to generate peptides for mass spectrometric analysis.
The digested protein can be analyzed by the ESI-TOF or MALDI-TOF and many different types of mass spectrometers. MALDI-TOF is often the widely used by people, because it allow a high throughput and several proteins can be analyzed in a single experiment, if it is complemented by MS/MS analysis.
About the author: Creative Proteomics is the proteomics division of CD Inc. And it offers a full range of drug development services. And we are staffed by many experienced scientists in handling hard-to-analyze samples. And we also in close cooperation with our partners, professional proteomics solutions are provided at the lowest cost level in the industry.
Links: http://www.creative-proteomics.com/Services/Peptide-mass-fingerprinting-PMF.htm
http:www.creative-proteomics.com