TABLE 1.
Half-maximal binding affinities and neutralization potencies of Fab Z13e1 and other affinity-enhanced variants of Fab Z13
| Ab | CDR L3 sequence | Half-maximal binding titers (nM)a
|
Neutralization IC50s (nM)b
|
||
|---|---|---|---|---|---|
| Rec. gp41 | Bio. peptide | HIV-1MN | HIV-1JR-FL | ||
| Z13 (wt) | QQRSDWPRT | 8.6 | 10 | 100 | >2,000 |
| Z13e1 | .A.LLL.Q. | 0.07 | 0.09 | <2.0 | 190 |
| Z13e4 | .SLMSM.Q. | 0.10 | 0.13 | 3.0 | 320 |
| Z13e6 | .SLLAL... | 0.13 | 0.10 | 3.6 | 240 |
| Z13e10 | .SLLVL... | 0.13 | 0.10 | 11 | 340 |
| Z13e12 | ....LHDG. | 0.10 | ND | ND | ND |
| Z13e15 | NDc | 0.40 | 0.44 | 11 | 600 |
| Z13e17 | .TGSAL... | 0.19 | ND | ND | ND |
| Z13A1 | ......Q.. | 2.0 | 37 | ND | ND |
| IgG 4E10 (positive control MAb) | 0.07 | 0.03 | 1.0 | 33 | |
a
Titers of Fabs against recombinant [Rec.] gp41JRFL [M41xt] and biotinylated [Bio.] peptide [69-3; SLWNWFDITNWLWRRK(biotin)-NH2] were determined in an ELISA.
b
Neutralization assay using single-round infectious HIV-1 pseudotyped with pNL4-3Luc and U87.CD4.CXCR4 (MN) or CCR5 (JR-FL) cells.
c
ND, not determined.