Changes of compressibility of low density lipoproteins following copper mediated oxidation

The methods of measuring the ultrasound velocity and density were used for study the adiabatic compressibility of low density lipoproteins (LDL) during their oxidation. We showed, that copper-mediated oxidation of LDL resulted in a decrease of apparent specific compressibility, phi(k)/beta0, of lipoproteins. The changes of ultrasound velocity and phi(k)/beta0 value started much earlier than the beginning of propagation phase corresponding to the fast increase in concentration of conjugated dienes, measured by absorption at 230 nm. It was assumed that the changes of compressibility could be in particularly due to increase in ordering of the phospholipids during reductive activation of Cu2+.