The swelling of bovine ligamentum nuchae as a function of pH

Abstract

The swelling and solubilization of foetal and adult bovine ligament over a range of pH values has been investigated. Maximum swelling occurs at pH 2.7 and pH 8.5 for both types of ligament. Above pH 13 complete solubilization occurs. Considerably greater swelling and solubilization occurs with foetal ligamentbelow pH12. The presence of 2[image]-sodium chloride markedly suppresses both swelling and solubilization. Above 1N- sodium hydroxide actual dehydration occurs andlittle or no protein is extracted. It is suggestedthat the intermolecular cross-links in a considerable proportion of foetal elastin are weak and that extraction with aqueous salt solution at pH 8.5 wouldprovide optimum conditions for extracting soluble proteins, including soluble elastin if this is present.