Differential scanning calorimetry (DSC) analysis of isolated liver and heart mitochondria

Abstract

Differential scanning calorimetry (DSC) is widely acknowledged for investigation of phase transition of membrane lipids as well as for denaturation of proteins. The aim of the present study was to analyse the thermal behaviour of the components of mitochondria isolated from male rat heart and liver in order to detect the phase transition events that might be responsible for different functional response of heart and liver mitochondria to febrile temperature as well as for the acute loss in membrane barrier function induced at the lower limit of supra-physiological temperature. The complex phase transition in liver and heart mitochondria was determined by DSC measurements in temperature range from 25 °C to 75 °C. The DSC results of heart mitochondria showed phase transition temperatures identical to those of liver mitochondria, except more intensive transition (1.7, 2- and 1.5-fold) at temperatures Tm 46, 54 and 60 °C, respectively, and an additional phase transition peak at Tm 33 °C which was inherent for heart mitochondria only. Keywords: heart mitochondria, liver mitochondria, phase transition, DSC, hyperthermia