Streptavidin (SA) is a homo-tetramer that has an extraordinarily high affinity for biotin (also known as vitamin B7). It is used extensively in molecular biology and bio-nanotechnology due to the streptavidin-biotin complex's resistance to organic solvents, denaturants (e.g. guanidinium chloride), detergents (e.g. SDS, Triton), proteolytic enzymes, and extremes of temperature and pH. Biotin binding increases the midpoint of temperature T_m of thermally induced denaturation from around 75°C to over 110°C at full biotin saturation. This thermostability is the highest reported for proteins coming from either mesophilic or thermophilic organisms.

thermal unfolding | unfolding kinetics | isothermal | PR-P-006