Table 1: 2219 antibody-mediated neutralization of psVs constructed from SF162 with the V3 loop replaced by the consensus C or consensus B V3 loop sequence with and without the indicated point mutations in the “Sequence” column. In vitro measured strong, weak, or no neutralization is indicated along with the IC50 (ug/mL) in the “Neutralization” column on the right. Numbering of mutated residues is from the beginning of the V3 loop with the starting cysteine being residue number 1 so that D25E (V3 loop numbering) is the same as D322E (numbering of residues from N-terminus of gp120). The “Flex” column is the structural flexibility of the V3 crown from positions 10 to 22 as assessed by ab initio folding: +++ indicates no energy gap and many conformations near the energy minimum suggesting a flexible structure; ++, +, and −indicate a spectrum of energy gaps of <2 U slightly more than the standard error of the energy function suggesting a partly flexible structure; −− indicates an energy gap >2 U indicating a rigid conformation. The “β-hairpin” column is the β-strand character of positions 12 to 14 as assessed in the same ab initio folding: +++ indicates that all three residues from 12 to 14 adopt canonical β-strand ϕ and Ψ angles in the lowest energy structure; ++ indicates that two of the three residues from 12 to 14 adopt canonical β-strand ϕ and Ψ angles; + indicates that two or more of the residues from 12 to 14 adopt canonical β-strand ϕ and Ψ angles, but that the overall structure does not form a β-hairpin. – and −− indicate that residues from 12 to 14 adopt canonical non-β-strand ϕ and Ψ angles.

SequenceFlexibilityβ-HairpinNaturalization
(IC50μg/mL)

Consensus B++++++Strong (0.001)
B-R18Q++++++Strong (0.001)
B-T22A+++++Strong (0.002)
C-I14V+++++Strong (0.01)
C-T19A++++Weak (0.02)
C-I14M++−−Weak (0.03)
C-I14F++Weak (0.1)
Consensus C−−−−None (0.15)
C-D25E−−−−None (0.15)
C-I14L−−None (0.15)