Stability of Bacteriophage T4 Short Tail Fiber

Abstract
Adsorption of Teven bacteriophages to the E. coli host cell is mediated by long and short tail fibers. Bacteriophage T4 short tail fiber protein p12 was used to investigate the stability against thermal and chemical denaturation. Purified p12 is thermostable with a melting point of 78C. Guanidinium chlorideinduced denaturation displayed strong hysteresis and an intermediate between 2 and 3 denaturant. The transitions occur at 1.5 and 3.2 denaturant as revealed by fluorescence spectroscopy and circular dichroism. The data suggest an equilibrium unfolding intermediate with a separate unfolding of the Cterminal knob domain and the shaft region.