Influence of protein net charge on the nucleic acid helix-destabilizing activity of various pancreatic ribonucleases.
Helix-destabilization of double-stranded poly[d(A-T)]induced by various homologous pancreatic ribonucleases which differ in their net charges has been studied under different ionic strength conditions. The response of the destabilizing activity of the various proteins to ionic strength is represented by bell-shaped curves, whose maxima are shifted to higher ionic strength values the higher the number of positive charges of the RNAase involved in the nucleic acid-protein complex. This observation is discussed, and a model proposed, that could explain the experimental results presented.
D000818:Animals; D002417:Cattle; D004268:DNA-Binding Proteins; D003670:Deer; D007700:Kinetics; D009691:Nucleic Acid Denaturation; D009994:Osmolar Concentration; D010179:Pancreas / Q000201:enzymology*; D011067:Poly dA-dT; D051381:Rats; D012260:Ribonucleases / Q000378:metabolism*; D012756:Sheep; D013045:Species Specificity; D013329:Structure-Activity Relationship; D013696:Temperature
D004268:DNA-Binding Proteins; D011067:Poly dA-dT; D012260:Ribonucleases