Parathyroid hormone is efficiently removed from the blood by a receptor-mediated process in the liver and is broken down into smaller peptide fragments.
A notation has been developed for indicating peptide fragments that arise from a tandem mass spectrum.
It performs mass spectrometry data analysis through a statistical evaluation of matches between observed and projected peptide fragments rather than cross correlation.
Although the proteasome normally produces very short peptide fragments, in some cases these products are themselves biologically active and functional molecules.
Pepsin breaks down the protein in the food into smaller particles, such as peptide fragments and amino acids.
Individual peptides are then analyzed for overall deuteration of each peptide fragment.
The mass of these peptide fragments is then calculated and compared to the peak list of measured peptide masses.
Chromogranin A is cleaved by an endogenous prohormone convertase to produce several peptide fragments.
Another method is fragment condensation, in which peptide fragments are coupled.
Additionally, sample preparation is easier once whole proteins have been digested into smaller peptide fragments.