Synthesis of fully active biotinylated analogues of parathyroid hormone and parathyroid hormone-related protein as tools for the characterization of parathyroid hormone receptors.

The synthesis, purification, and characterization of biotinylated analogues of parathyroid hormone (PTH) and PTH-related protein (PTHrP) are described. A novel methodology was developed which allowed the selective biotinylation during solid-phase synthesis of either the Lys 13 or Lys 26 residue in PTH/PTHrP sequences. Incorporation of orthogonally protected N α -Boc-Lys(N e -Fmoc) at a selected position in the sequence, followed by selective side-chain deprotection and biotinylation of the e-amino group, permitted modification of the specific lysine only