Electrometric and spectrophotometric titration of histone and deoxyribonucleohistone.

摘要: The viscosity and sedimentation properties of whole histone, the weight-average molecular weight which was 40,000, showed that at neutral pH molecule a relatively stiff coil unfolded low pH. electrometric spectrophotometric titration curves histone all ionisable groups present in titrated range 3 to 11. curve explicable terms non-uniform distribution charge on molecule. lysine arginine residues appeared be grouped together polypeptide chain, whereas carboxyl, histidyl tyrosyl were situated regions remote from positively charged groups. moiety deoxyribonucleohistone imidazole accessible for titration, but only 80% had 12·0. It concluded “masked” linked by ionic bonds phosphate DNA. results consistent with model one or other grooves DNA groups, leaving outer surface complex.