Physical properties of ribosomal proteins isolated under different conditions from the Escherichia coli 50 S subunit.

Physical properties of ribosomal proteins obtained with or without denaturating agents were compared. CD measurements and NMR studies have shown that proteins L2, L19, L24 and L30 isolated under denaturing conditions have the same properties as those prepared avoiding denaturating agents. CD and NMR spectra of proteins L1, L6, L11, L23, L25 and L29 obtained by us under denaturating conditions practically coincide with the data for the same proteins reported under 'mild' conditions. These findings suggest that the differences of reported physical properties can be due to different procedures of protein renaturation rather than to the methods of their isolation.