The conformational changes in myoglobin, treated by microbubbling of supercritical carbon dioxide (SC-CO2), were investigated by measuring the circular dichroism spectra in the ultraviolet range and compared with those in other proteins (ovoalbumin, bovine serum albumin, and β-lactoglobulin). Irreversible unfoldings were observed after the microbubbling of SC-CO2 at 35 °C and 30 MPa for 30 min. The degree of unfolding depended on the number of intramolecular S-S bonds. α-Helix contents of myoglobin decreased with increasing density of SC-CO2. Unfoldings of myoglobin induced by heating, pH-lowering, and the addition of a denaturant were reversible. The irreversible unfolding of myoglobin was also observed by the bubbling of gaseous CO2 under atmospheric pressure, but heating was required.
All Science Journal Classification (ASJC) codes
- Agricultural and Biological Sciences(all)