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

•A 199 residue recombinant spider wrapping silk subunit (W1) is characterized.•Structural integrity is maintained with temperature and pH variation and storage.•Reversible denaturation demonstrates a midpoint of ∼71°C with minimal aggregation.•W1 self-assembles into ∼20–300nm sized particles in near-physiological buffer.•Nanoparticle self-assembly occurs above a critical concentration of ∼20μM.