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Chromatography of polypeptides and proteins on hydroxyapatite columns

1968; Elsevier BV; Volume: 160; Issue: 3 Linguagem: Inglês

10.1016/0005-2795(68)90203-1

1878-1454

Giorgio Bernardi, T. Kawasaki,

Protein Hydrolysis and Bioactive Peptides

Chromatography of a number of water-soluble homo- and heteropolypeptides on hydroxyapatite columns has shown that only those containing carboxyl groups (poly-l-aspartate, poly-l-glutamate and their copolymers) are adsorbed by hydroxyapatite. The presence of urea or salt in the eluting buffer does not modify the elution molarity of poly-l-glutamate. It is likely that in the case of proteins, too, the chemical groups responsible for the interaction with hydroxyapatite are the carboxyl groups. A special case is that of phosphoproteins where a very strong interaction with hydroxyapatite is due to the presence of the protein-phosphate groups. Denaturation of proteins reduces their affinity for hydroxyapatite probably by reducing the number of carboxyl groups available for the interaction and by destroying the clusters of carboxyl groups present on the surface of native proteins and responsible for the interaction.