Structure of a V(H)H isolated from a naïve phage display library

OBJECTIVE: To determine the X-ray structure and biophysical properties of a Camelid V(H)H isolated from a naïve phage display library. RESULTS: Single domain antibodies (V(H)H) derived from the unique immune system of the Camelidae family have gained traction as useful tools for biotechnology as well as a source of potentially novel therapeutics. Here we report the structure and biophysical characterization of a V(H)H originally isolated from a naïve camelid phage display library. V(H)H R419 has a melting temperate of 66 °C and was found to be a monomer in solution. The protein crystallized in space group P6(5)22 and the structure was solved by molecular replacement to a resolution of 1.5 Å. The structure revealed a flat paratope with CDR loops that could be classified into existing canonical loop structures. A combination of high expression yield, stability and rapid crystallization might make R419 into a candidate scaffold for CDR grafting and homology modeling.