Aligned structure of the B1 receptor peptide ligands used in the present study and their affinities in two assays (competition of [3H]Lys-des-Arg9-BK to B1 receptors expressed by smooth muscle cells; competition for the hydrolysis of l-Ala-pNA by the aminopeptidase present in smooth muscle cell membranes)
The B1 receptor binding Ki values for the nonpeptide compounds 11 and A are 0.013 and 0.032 nM, respectively.
Peptide Sequence | B1 Receptor Binding Ki | Enzyme Ki | |||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| nM | μM | ||||||||||||||||||||
| Agonists | |||||||||||||||||||||
| des-Arg9-BK | NH3+-Arg | Pro | Pro | Gly | Phe | Ser | Pro | Phe-COO- | 24.8 | 86.7 | |||||||||||
| Lys-des-Arg9-BK | NH3+-Lys | Arg | Pro | Pro | Gly | Phe | Ser | Pro | Phe-COO- | 0.14 | 14.3 | ||||||||||
| Lys-[d-Phe8]des-Arg9-BK | NH3+-Lys | Arg | Pro | Pro | Gly | Phe | Ser | Pro | d-Phe-COO- | 0.28 | 16.8 | ||||||||||
| Sar-[d-Phe8]des-Arg9-BK | Sar | Arg | Pro | Pro | Gly | Phe | Ser | Pro | d-Phe-COO- | 2.80 | >1000 | ||||||||||
| Antagonists | |||||||||||||||||||||
| [Leu8]des-Arg9-BK | NH3+-Arg | Pro | Pro | Gly | Phe | Ser | Pro | Leu-COO- | 54.3 | 124 | |||||||||||
| Lys[Leu8]des-Arg9-BK | NH3+-Lys | Arg | Pro | Pro | Gly | Phe | Ser | Pro | Leu-COO- | 0.52 | 26.2 | ||||||||||
| Ac-Lys[Leu8]des-Arg9-BK | Ac-Lys | Arg | Pro | Pro | Gly | Phe | Ser | Pro | Leu-COO- | 7.53 | >1000 | ||||||||||
| B-10350 | NH3+-Lys | Lys | Arg | Pro | Hyp | Gly | Igl | Ser | d-Tic | CpG-COO- | 0.74 | 1.89 | |||||||||
Ac, N-acetyl; CpG, α-cyclopentylglycine; Hyp, trans-4-hydroxyproline; Igl, α-(2-indanyl)glycine; Sar, sarcosine (N-methylglycine); Tic, 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid.