Scanning calorimetric studies of some protein-protein interactions involving myoglobin

To aid in understanding the formation of cooked meat haemoprotein, the thermal denaturation behaviour of metmyoglobin in 0·05(M) phosphate solutions (pH 6·0) of bovine serum albumin and ovalbumin was analysed by differential scanning calorimetry. Although, in general, there is minimal interaction between proteins prior to and during thermal denaturation, it was found that in the presence of an excess of protein of relatively low thermal stability (bovine serum albumin) myoglobin denatures and precipitates with this protein. It is suggested that this destabilisation of myoglobin is due to specific interaction between the denatured protein and the haematin of a conformationally altered, but undenatured, myoglobin.