Fig. 3.

PG9 and PG16 binding to gp120 and gp140 proteins. (a) Purified monomeric gp120 (m-gp120), monomeric gp140 (m-gp140), or trimeric gp140 (t-gp140) was incubated with PG9 or PG16 and immunoprecipitated as described in Materials and Methods. Molecular mass markers are indicated. Lanes 1, PG9; lanes 2, PG16; lanes 3, 10 ng of protein was directly applied to the SDS-PAGE gels. (b) ELISA binding curves are shown for monomeric gp120, monomeric gp140, and trimeric gp140 derived from Q259d2.17 and SF162K160N. An HIV⁺ plasma pool or purified IgG from that same pool was used as a control to confirm the presence of similar amounts of gp120 and gp140 on the ELISA plates. The error bars indicate standard deviations.