Figure 4

Identification of SST-14 residues involved in Sstr2 activation. Sstr-2 transgenic animals were tested for response to SST-14 and five variants with single alanine substitutions at residues 6–10. No avoidance behaviour was observed with 25 μM of Trp8Δ Ala and Lys9Δ Ala SST-14 analogues while residual avoidance behaviour was found with Phe7Δ Ala and Thr10Δ Ala. Sstr2 transgenic animals were repelled by the Phe6Δ Ala analogue, indicating that Phe6 is not essential for receptor:ligand interaction. Each data point represents an average of at least five independent assays for wild type and each respective strain. Error bars denote the standard error of the mean. Asterisks indicate a statistically significant difference between the avoidance index of the transgenic animals for the Trp8Δ Ala and Lys9Δ Ala analogues and native SST-14 agonist (*p ≤ 0.05, **p ≤ 0.01).