TABLE 1

Receptor binding site affinity values for all receptor constructs used

The table classifies the receptor construct and lists the relevant pKD value for [33P]H2 relaxin binding. pKD values are expressed as means ± the standard error of the mean of five to seven experiments.




Receptor Construct

pKD
Native receptors RXFP1 9.26 ± 0.22
RXFP2 (high-affinity site) 9.24 ± 0.30
RXFP2 (low-affinity site) 8.35 ± 0.10***
Chimeric receptors RXFP1/2 9.57 ± 0.18
RXFP2/1 9.33 ± 0.12
Ectodomain-only constructs RXFP1-BP 9.78 ± 0.20

RXFP2-BP
9.28 ± 0.36
  • *** p < 0.001 versus high-affinity RXFP2 site (unpaired t test); p < 0.05 versus the low-affinity RXFP2 site (unpaired t test).