Peptide Mass Fingerprinting (PMF) Simply Explained
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- Опубліковано 27 лип 2024
- Peptide mass fingerprint is a high throughput method used to identify proteins. A peptide is a protein fragment and these fragments is what creates a fingerprint for the protein.
Peptide mass fingerprinting works by using a cleaving enzyme such as Trypsin to cut the protein of interest into smaller fragments or peptides. Then one uses MALDI-TOF to establish a mass to charge (m/z) ratio for these peptides which can be compared to theoretical masses of these same protein peptides in order to find a match. These theoretical masses have been acquired through the use of a computer program that uses a database containing the relevant proteins. These programs can then cut these proteins in silico (simulates) into peptides. Then it can calculate the absolute or theoretical masses of these peptides which are used for comparison.
Peptide mass fingerprinting can be carried out step-by-step in the following manner.
1. First the protein is separated by using gel electrophoresis
2. Protein digestion by proteolytic enzyme usually Trypsin
3. Mass Spectrometric analysis, such as MALDI-TOF or ESI-TOF
4. Software performs in silico digestion on database proteins with the same enzyme used in the experimental digestion, generating a theoretical peak list
There are two main advantages of peptide mass fingerprinting.
1. Unexpected post-translational modifications leads to only a marginally loss in data, which is not enough to affect the outcome
2. PMF is in at least some cases more specific than tandem mass spectrometry thanks to the use of multiple peptides
The greatest disadvantages of PMF is that the protein of interest has to be present in a database, or the process will not work.
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Thank you for your clear explanation! If it is possible, explain the application of MALDESI or ESI in biology.
That would be great!
that was super clear, thank you!
Happy to hear that! Thank you for your nice comment😇👍
Very good bro!!llove from india
Thank you!🙏
Nice job but i want to identify how i can use GC-MS to identify biomarker
Without knowing anything about the protein how can we digest the protein theoretically and compare. Please explain mate
Yeah, sorry if that was left out in the video. So, MALDI-TOF devices usually have access to databases of reference spectra for different proteins and molecules. The idea is that the same PMF technique has been used on a bunch of proteins previously and then you can pattern match the unknown protein to one of those😀