Renal V₂ Vasopressin Receptor Proteins: Identification and Enrichment

Abstract

The synthesis of the tritium labelled photoreactive analogue of 1-deamino-vasopressin [1-(3-mercaptopropionic acid, 8-(N⁶-4-azidophenylamidino)-lysine]vasopressin is described. This analogue retains a high affinity for hepatic V₁ and renal V₂ vasopressin receptors (apparent dissociation constant K_Dβ1-2 nM). A membrane protein from bovine kidney and pig kidney with an apparent relative molecular mass (M_r) of 30 000 was preferentially labelled and with lower yield a protein band with a M_r-value of 50 000 to 60 000. The photolabelled 30 000-M_r protein from bovine kidney was enriched by size-exclusion chromatography and by reversed-phase-high-performance liquid chromatography.