Conformation and some properties of bovine .ALPHA.s2-group-casein.

Abstract

The conformation and some properties of bovine αs2-group-casein (a mixture of αs2-, αs3- and αs4-casein) were investigated. The secondary structure was estimated from Moffitt parameters and circular dichroism spectra in the ultraviolet region. αs2-Group-casein contained about 20% of α-helix and a small amount of β-form. The higher content of α-helix in αs2-group-casein than in αs1-casein is considered to be due to the lower content of proline. It is shown that heat treatment at 90°C for 15 min caused about 35 %destruction of the α-helix. It is also shownby charge shift electrophoresis that αs2-group-casein has an amphiphilic structure.