The use of computed activity coefficients in Raoult's reference system, for n-alcohol/water mixtures, and their application to the study of proteins.
Activity coefficients of alcohols in Raoult's reference system have been calculated. Using data from papers dealing with transition temperatures in the presence of n-alcohols, lipase deactivation and competitive inhibition by n-alcohols of pepsin and alpha-chymotrypsin, it is shown that the conversion of concentrations into activities (using Pierotti's equation) profoundly affects the original data. Within experimental error, if inhibition constants by alcohols keep the same value, lupase deactivation becomes independent of the length of the alcohol chain, and except for butanol, transition temperature is no longer dependent on the number of methylene groups. Interpretations which take into account the thermodynamic reference system and final environment are related to the fact that alcohol molecules bind to some inner parts of the proteins.
D000438:Alcohols; D001665:Binding Sites; D002918:Chymotrypsin; D003201:Computers; D007700:Kinetics; D008049:Lipase; D008433:Mathematics; D010434:Pepsin A; D011485:Protein Binding; D011506:Proteins; D012260:Ribonucleases; D013696:Temperature; D013816:Thermodynamics; D014867:Water
D000438:Alcohols; D011506:Proteins; D014867:Water; D012260:Ribonucleases; D008049:Lipase; D002918:Chymotrypsin; D010434:Pepsin A