Kisspeptin Antagonists - Kisspeptin Signaling in Reproductive Biology - page 166

Fig. 8.6 Table detailing all KP-10 peptide analogues. Table showing the peptide analogues tested
with results for binding and stimulation of IP and calcium release. Antagonistic results for IP and
calcium are also shown. The four antagonists found are highlighted in yellow and other promising
analogues in blue
signifi cantly improved antagonism to 81%; and D -Ala 1 substitution (peptide 234)
signifi cantly increased antagonism further to 93%, with an IC 50 of 7×10 −8 M.
However, D -Trp 1 (peptide 243) or D -Phe 1 (peptide 244) substitution at this position did
not increase the antagonism (Fig. 8.6). This suggests that removing the charge and
hydrogen bonding from this position is important for antagonism and that steric
hindrance at this position is detrimental to antagonistic activity. Amino acid