[Conformational changes in rabbit muscle aldolase under normal conditions and following prolonged starvation]

The experiments were aimed at studying conformation differences of muscle aldolase in normal rabbits and those fasting for a long time and at finding the areas of polypeptide chains affected by the changes. For this purpose the difference, temperature- and solvent-perturbation spectra of the compared proteins were examined. On the basis of the data obtained on the same amount of chromophore groups in both proteins a conclusion is drawn on a more hydrophobic surrounding of tyrosine and tryptophan residues in aldolase of the long-fasting animals. When determing the content of the tyrosine and tryptophan surface residues an increase (from 13 to 21) was found in the number of the tyrosine residues in aldolase of the long-fasting animals. An assumption is advanced on localization of the primary structure changes in the molecule sites rich in chromophore groups or those located closer to them.