Table 1

HPLC purification of the Drosophila GnRHR receptor ligand

ColumnGradient of acetonitrile in 0.1% trifluoroacetic acidRetention time of the peptide, min
1. Spherisorb C-18 (20 × 250 mm; 5 μm; 80 Å)10–60% (40 min; 8 ml/min)27.0–28.0
2. Partisil ODS-3 (4 × 250 mm; 5 μm; 60 Å)10–60% (30 min; 1 ml/min)17.0–18.0
3. LiChrospher RPSelect (4 × 250 mm; 5 μm; 60 Å)20–50% (30 min; 1 ml/min)16.5–16.8
4. Nucleosil C-18 (4 × 250 mm; 5 μm, 300 Å)20–30% (40 min; 1 ml/min)19.06
5. Spherisorb C-18-2 (4 × 250 mm; 5 μm; 80 Å)20–40% (40 min; 1 ml/min)20.66
6. Nucleosil C-18 (4 × 250 mm; 5 μm; 120 Å)20–30% (40 min; 1 ml/min)25.55
7. Spherisorb C-18-2 (4 × 250 mm; 5 μm; 80 Å)20–30% (40 min; 1 ml/min)20.91
  • The starting material was an aqueous extract from 400 g of third-instar larvae (see Materials and Methods).