Synthesis and use of specific isotopically labeled peptide hormones for studies of conformation, dynamics, and hormone-protein interactions

The synthesis of amino acids specifically labeled with deuterium at the Cα and Cβ positions, with carbon-13 at the C', Cα, and Cβ carbon atoms of most amino acids, with deuterium and/or carbon-13 at the 3' and 5' positions of tyrosine, phenylalanine, and related amino acids can be readily accomplished. These compounds can be resolved into their purified enantiomers if desired, and the pure enantiomers (or enantiomeric mixture) can be suitably protected for incorporation into peptide hormones or neurotransmitters by total synthesis. The diastereoisomeric peptides can be purified by partition chromatography or preparative reversed phase high pressure liquid chromatography. These peptide hormone derivatives and their analogues can be used for a wide variety of biochemical and biophysical studies including: a) the unambiguous assignment of 1H and 13C NMR spectra for conformational studies; b) careful examination of the chemical and dynamic properties of individual amino acid residues or of individual atoms in specific amino acid residues of these peptides; c) simplification of complex spectral regions with overlapping signals for assignments of other non-labeled amino acid residues; d) examination of conformational and dynamic properties of peptide hormones and neurotransmitters as they interact with receptors and other macromolecules important to their biological activity. 40 refs