Immunologic mapping of the amino‐ and carboxy‐termini of the turkey erythrocyte β‐adrenergic receptor; Selective proteolysis of both domains

Peptide‐directed antibodies were used to map the N‐ and C‐termini of the turkey erythrocyte β‐adrenergic receptor, the full length recombinant receptor expressed in Sf9 cells, and a mutant that terminates after residue 424 (T424). Both forms of the natural receptor (P40 and P50): were proteolytically clipped between residues 419 and 424, P40, but not P50, is also proteolyzed between residues 14 and 28. Truncation mutants, but not full length receptors, also display both large and small forms. The short form or T424 is formed by proteolysis after residue 14, but neither form is proteolyzed in the C‐terminal region. The wild type recombinant receptor is not proteolyzed.