The selected mutant target is counted as surviving whenever its exact sequence remains intact in the parent or a shorter fragment.
Enzyme guide
Circulation relevance depends on the peptide, enzyme access and active concentration. There is no universal ranking of DPP4, FAP and ACE.
Can we estimate relative contributions?
Human plasma experiments found ACE dominated dilute bradykinin degradation while CPN dominated at higher concentrations. DPP4-mediated trimming is established for particular hormones. Those findings do not supply relative rates for these vaccine sequences.
Measure parent and epitope-bearing products over time with selective enzyme inhibitors, then fit rates for each retained fragment. Purified-enzyme kinetics and active concentrations can support the model; abundance or a motif alone cannot give a circulation rate.
Coverage and disclosed references
Constructs without a resolved mutant target remain visible
Disclosed targets retained as references
What would establish epitope survival?
An LC-MS time course measuring the intact parent and products retaining the selected target, with peptide chemistry, assay matrix and sampling conditions recorded. Serum preparation and anticoagulants can alter protease activity; serum estimates do not directly establish whole-blood or human circulation lifetimes.
Structural constraints, terminal changes, side groups and protein binding can prolong lifetime. These vaccine inputs assume unmodified linear L-peptides with free termini. Neither model establishes vaccine-fragment accuracy.
A cut inside the selected exact target splits it. That does not establish loss of all alternative epitopes or productive MHC presentation. Uptake and processing remain separate biological steps.