Why is Trypsin Normally Used in Protein Mass Spectrometry

Question

Why is trypsin normally used in protein mass spectrometry?
A) It is a positive control found in almost all animal cells.
B) It is used as a standard to define the upper and lower boundaries of mass sensitivity.
C) It cuts the protein into smaller peptides,which can be more accurately analyzed than longer fragments.
D) It is a useful general capture molecule for affinity purification.
E) It is an effective antibiotic to suppress contamination from microbes.

Accepted Answer

Trypsin is a proteolytic enzyme that cleaves peptide bonds on the C-terminal side of basic amino acids like lysine and arginine. This specificity results in the generation of smaller peptides which are easier to analyze by mass spectrometry. Therefore, trypsin is commonly used to proteolyze protein samples prior to MS analysis.