Abstract
Molecular weight determinations were carried out on a hypocalcemic protein purified from bovine parotid gland by sedimentation equilibrium, gel chromatography on Sepharose 6B in 6 M guanidine hydrochloride (Gun HC1), and viscometry in 6 M Gun HC1 0.1 M mercaptoethanol, and the values obtained were 45000, 47000, and 45700, respectively. These results agreed well with the result (48000) from sodium dodecyl sulfate polyacrylamide gel electrophoresis. The optical rotatory dispersion and circular dichroism spectra of the purified hypocalcemic protein showed that the contents of α-helix, β-structure, and random coil were 54, 26, and 20%, respectively. It was found that this protein contains large amounts of α-helix and thereby has a rigid structure.
