Solubility of chicken breast muscle proteins in solutions of low ionic strength

Essentially all of the proteins of chicken breast muscle were soluble in sodium chloride solutions of physiological ionic strength or less and neutral pH. However, there was a critical order of treatment necessary to accomplish this. After removal of those proteins solubilized by homogenizing the tissue 1:10 (w/v) in water, it was necessary to solubilize a fraction of the remaining proteins in moderate concentrations (25-150 mM) of sodium chloride at neutral pH before the remaining proteins could be solubilized in water. Solubilization of chicken breast muscle proteins in water could be prevented or reversed by salt solutions of low concentration, suggesting that most of the solubility was not directly caused by proteolysis. SDS-polyacrylamide gel electrophoresis indicated that removal of specific peptides by moderate concentrations of sodium chloride at neutral pH was correlated with removal of the restriction on the water solubility of the remaining proteins.