Figure 2.

Purification of peptides from neurons VD1 and RPD2 using reverse-phase HPLC. Peptides were extracted from 800 VD1 and RPD2 neurons and resolved on a C18 column using an acetonitrile gradient in 7.5 mm TFA as a counter ion. Fractions eluting at 23,42,43,45,48,51, 53, 54, 55, 67, and 113 min contained molecules with masses that corresponded to molecules C, H2, H, G2, G, F2, F, D2, E2, I, and K, respectively, of the VD1 mass spectra in Figure 1. The elution positions of peptides F, G, and H as well as those of the previously identified α1, α2, and β peptides (Bogerd et al., 1994) and SCPs (Jimenez et al., 1998) are indicated. In some cases, to obtain pure peptide, it was necessary to further resolve peptides on a second gradient using HCl as a counter ion. The dashed line indicates the gradient of acetonitrile.