Figure 4. Maleimide modification of the internal cysteines of reduced nanobodies upon thermal unfolding.

Indicated nanobodies, expressed in the reductive cytoplasm of Escherichia coli BLR, were incubated at the indicated temperatures in the presence or absence of a two-fold molar excess of biotin-PEG₂₃-maleimide (1.45 kDa) in buffer. The addition of 6 M urea served as a positive control for maleimide modification of the internal cysteines upon chemical unfolding.

DOI: http://dx.doi.org/10.7554/eLife.11349.007