|Title||Rational Design of Nanobody80 Loop Peptidomimetics: Towards Biased β Adrenergic Receptor Ligands.|
|Publication Type||Journal Article|
|Year of Publication||2017|
|Authors||Martin, C., S. L. C. Moors, M. Danielsen, C. Betti, C. Fabris, D. Sejer Pedersen, E. Pardon, M. Peyressatre, K. Fehér, J. C. Martins, J. Mosolff Mathiesen, M. C. Morris, N. Devoogdt, V. Caveliers, F. De Proft, J. Steyaert, and S. Ballet|
|Date Published||2017 Jul 18|
G protein-coupled receptors (GPCRs) play an important role in many cellular responses; as such, their mechanism of action is of utmost interest. To gain insight into the active conformation of GPCRs, the X-ray crystal structures of nanobody (Nb)-stabilized β -adrenergic receptor (β AR) have been reported. Nb80, in particular, is able to bind the intracellular G protein binding site of β AR and stabilize the receptor in an active conformation. Within Nb80, the complementarity-determining region 3 (CDR3) is responsible for most of the binding interactions. Hence, we hypothesized that peptidomimetics of the CDR3 loop might be sufficient for binding to the receptor, inhibiting the interaction of β AR with intracellular GPCR interacting proteins (e.g., G proteins). Based on previous crystallographic data, a set of peptidomimetics were synthesized that, similar to the Nb80 CDR3 loop, adopt a β-hairpin conformation. Syntheses, conformational analysis, binding and functional in vitro assays, as well as internalization experiments, were performed. We demonstrate that peptidomimetics can structurally mimic the CDR3 loop of a nanobody and its function by inhibiting G protein coupling as measured by partial inhibition of cAMP production.
Rational Design of Nanobody80 Loop Peptidomimetics: Towards Biased β Adrenergic Receptor Ligands.