TABLE 1.

Alanine and variable loop-deleted mutants used in this study and their effect on 2G12 binding

Position in gp120aMutationbAntibody affinity relative to wild type (%)cEffectd
V1ΔV1175N
V1/V2ΔV1/2173N
V3ΔV367N
256S256A150N
262N262Ae94N
265L265A118N
268E268A56N
276N276Af215I
288L288A109N
289N289Ae58N
290E290A122N
292V292A137N
293K293A181N
295N295Ae2D
297T297S100N
299P299A107N
301N301Af73N
302N302A140N
313P313A101N
329A329K121N
330H330A95N
332N332Ae3D
334S334T13D
335R335A117N
336A336K54N
337Q337A138N
339N339Ae8D
340N340A178N
343K343A116N
344Q344A227I
348K348A146N
350R350A99N
353F353A22D
355N355Af155N
360V360A124N
362T362A102N
363H363A97N
365S365A1173I
366G366A196N
368D368A197N
369P369A118N
370E370A174N
384Y384A122N
386N386Ae26D
388T388A158N
389Q389A77N
392N392Ae5D
397N397Ae148N
403E403A122N
404K404A32D
406S406A33D
408T408A40D
409E409A62N
410G410A86N
411N411Af136N
413T413S120N
414I414A146N
415I415A72N
416L416A2D
417P417A86N
419R419A111N
420I420A110N
421K421A23D
445C445A77N
450T450A108N
458G458A349I
463S463A107N
  • a Position refers to gp120 position in HxB2 sequence. The position of an asparagine residue at which the N-linked glycan is implicated in 2G12 binding is underlined.

  • b Mutation XnnnY, where amino acid X at position nnn is substituted by Y; Δ denotes the following amino acid deletions: ΔV1 (amino acids 134 to 154); ΔV1/V2 (amino acids 134 to 154 and 160 to 193); ΔV3 (amino acids 303 to 324).

  • c Apparent affinities were calculated as the antibody concentration at 50% maximal binding. Relative affinities were calculated using the formula [(apparent affinity of wild type)/(apparent affinity of mutant)] × 100%.

  • d Effect on antibody affinity: N, no change; D, decrease; I, increase.

  • e Oligomannose carbohydrate.

  • f Complex carbohydrate.