Nanoparticle self-assembly by a highly stable recombinant spider wrapping silk protein subunit

Artificial spider silk proteins may form fibers with exceptional strength and elasticity. Wrapping silk, or aciniform silk, is the toughest of the spider silks, and has a very different protein composition than other spider silks. Here, we present the characterization of an aciniform protein (AcSp1) subunit named W-1, consisting of one AcSp1 199 residue repeat unit from Argiope trifasciata. The structural integrity of recombinant W-1 is demonstrated in a variety of buffer conditions and time points. Furthermore, we show that W-1 has a high thermal stability with reversible denaturation at similar to 71 degrees C and forms self-assembled nanoparticle in near-physiological conditions. W-1 therefore represents a highly stable and structurally robust module for protein-based nanoparticle formation. (C) 2013 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.