A Peptide Filtering Relation Quantifies MHC Class I Peptide Optimization
Figure 5
Filtering relation of MHC class I peptide optimization.
(A) Consider a population of MHC complexes containing peptides with off-rate
.
denotes the expected number of MHC complexes that will egress before the peptide can escape.
denotes the expected proportion of egressed MHC complexes that will contain peptides with off-rate
. This defines a measure of peptide optimization. We plot
and
as functions of
for three peptides with different off-rates and the same initial populations. Maximal optimization is achieved when
, with
(dashed lines). (B) Consider a population of
tapasin-MHC complexes containing peptides with off-rate
.
denotes the expected number of MHC complexes that will unbind from tapasin and egress before the peptide can escape, where
.
is defined as in A. We plot
and
as functions of
with
(black line in A). Maximal optimization is achieved when
, with
.