1. Improved GPCR ligands from nanobody tethering.
- Author
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Cheloha RW, Fischer FA, Woodham AW, Daley E, Suminski N, Gardella TJ, and Ploegh HL
- Subjects
- Amino Acid Sequence, Animals, Female, HEK293 Cells, Humans, Ligands, Mice, Models, Molecular, Parathyroid Hormone metabolism, Peptides chemistry, Peptides metabolism, Protein Binding, Receptor, Parathyroid Hormone, Type 1 metabolism, Receptors, G-Protein-Coupled metabolism, Single-Domain Antibodies metabolism
- Abstract
Antibodies conjugated to bioactive compounds allow targeted delivery of therapeutics to cell types of choice based on that antibody's specificity. Here we develop a new type of conjugate that consists of a nanobody and a peptidic ligand for a G protein-coupled receptor (GPCR), fused via their C-termini. We address activation of parathyroid hormone receptor-1 (PTHR1) and improve the signaling activity and specificity of otherwise poorly active N-terminal peptide fragments of PTH by conjugating them to nanobodies (VHHs) that recognize PTHR1. These C-to-C conjugates show biological activity superior to that of the parent fragment peptide in vitro. In an exploratory experiment in mice, a VHH-PTH peptide conjugate showed biological activity, whereas the corresponding free peptide did not. The lead conjugate also possesses selectivity for PTHR1 superior to that of PTH(1-34). This design approach, dubbed "conjugation of ligands and antibodies for membrane proteins" (CLAMP), can yield ligands with high potency and specificity.
- Published
- 2020
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