Figure 1.
Dependence of the stoichiometry of neutralization, , on the trimer's infectiousness.
Wild-type envelope proteins are colored black, mutant envelope proteins red and antibodies green. Due to saturation with antibodies prior to the infectivity experiments, all wild-type envelope proteins are assumed to be bound. Functional trimers are marked with “+”, non-functional ones with “−”.
Figure 2.
Functionality, i.e. probability of a trimer neutralized by some antibodies to take part in attachment to virus.
Table 1.
Parameter definitions.
Figure 3.
The relative infectivity in the basic model predicted by equation 4 as a function of the fraction of neutralization resistant envelope proteins.
For plot (A) and (B) we assume that each virion has exactly 10 trimers. For plot (A) and (C) the stoichiometry parameter of entry equals
, according to our estimates in [1]. (A) Dependence of the relative infectivity on the stoichiometry parameter
. (B) Dependence of the relative infectivity on the stoichiometry of entry
. (C) Dependence of the relative infectivity on the mean and variance of trimer numbers. For this plot the stoichiometry parameter
is set to
. Solid lines are based on a mean number of trimers equal to 10. Dashed lines have a mean trimer number of 36. For the black curves the number of trimers is exactly 10 respectively 36 and the distribution of trimer numbers for the red curves are discrete uniform distributions with 2 to 18 respectively 0 to 72 trimers.
Figure 4.
Loss of distinguishability of estimates of the stoichiometry of neutralization in the imperfect transfection model and the segregation model.
(A) Dependence of the predicted relative infectivity in the imperfect transfection model on the stoichiometry parameter , the entry parameters for this figure are
and
. (B) The area between predictions for
and
is depicted in dependence of the variance coefficient
. The decrease of this area size with increasing
makes the differentiation between different stoichiometries of neutralization difficult for high values of
. (C) and (D) show the same phenomenon for the segregation model. The parameters for (C) are
and
. The stoichiometry of entry for (B) and (D) is
.
Figure 5.
Relative infectivity curves for the best estimate of the stoichiometry of neutralization in the different models.
The imperfect transfection model and the segregation model are omitted due to the lack of reliability of the estimates. In the other models, the best fit is obtained for . The entry parameters are included from the estimation of the entry parameters in [1]:
for the basic model,
for the proximity model and
for the soft threshold model.