H, C and N backbone chemical shift assignments of camelid single-domain antibodies against active state µ-opioid receptor.

Nanobodies are single chain antibodies that have become a highly valuable and versatile tool for biomolecular and therapeutic research. One application field is the stabilization of active states of flexible proteins, among which G-protein coupled receptors represent a very important class of membrane proteins. Here we present the backbone and side-chain assignment of the H, C and N resonances of Nb33 and Nb39, two nanobodies that recognize and stabilize the µ-opioid receptor to opioids in its active agonist-bound conformation. In addition, we present a comparison of their secondary structures as derived from NMR chemical shifts.