Table 1.

Persistence of HIV-1 on FDC

Nominal (mean) valence n	Best-fit crosslinking constant KxRT	Expected dissociation time t1, days	Extinction time, days	Smallest valence for which
				t1 > 1 yr	t1 > 10 yr
10	3.840	21	555	12	14
20	1.1427	21	561	24	28
30	0.6533	21	562	37	41
40	0.45527	21	564	49	55
50	0.34885	21	564	61	69
60	0.2826	21	564	73	83
70	0.23742	21	564	85	96
80	0.20468	21	565	97	110
90	0.17986	21	565	109	124
100	0.1604	21	566	121	137

The values of n and K_xR_T given in each row result, according to Eqs. 1 and 2, in a 10,000-fold drop in viral load on FDC between days 2 and 180 of treatment, consistent with the drop observed by Cavert et al. (4). A fitting procedure (bisection) was used to determine K_xR_T after a nominal value was specified for n. The expected dissociation time t₁ in column 3 is calculated from Eq. 4. The extinction time in column 4 is the time required to reduce the mean number of bound virions from 10¹¹ virions, which is the estimated total number of virions on FDC (3), to a single virion. The extinction time is calculated from Eq. 5 with the initial condition P₁₁ = 1 (each virion is initially bound at a single site). The valences given in columns 5 and 6 are the smallest valences for which t₁ is greater than or equal to 1 yr and 10 yr, respectively, according to Eq. 4 (on the basis of the value of K_xR_T in column 2). All calculations assume k_r = k_−x = 0.1 s⁻¹.