Unfolded 30 S ribosomal subunits

The 30 S ribosomal subunit from Escherichia coli was unfolded into discrete particles upon which physical studies were carried out. These particles were found to be homogeneous and were characterized using sedimentation velocity, diffusion, density and viscosity measurements. The results of these studies clearly certify two distinct stages of unfolding, neither involving a significant loss of protein. However, the results also clearly show that the measurement of only one characteristic (e.g., the sedimentation coefficient) is not sufficient to suggest a structural change. The significance and importance of the apparent specific volume are stressed.