High performance liquid chromatographic properties of peptides and proteins on a dihydroxyalkyl bonded silica stationary phase.

The chromatographic behavior of biologically relevant peptides and proteins in the molecular weight range between 200 and 200,000 dalton units were studied on a size exclusion matrix column consisting of an aqueous compatible dihydroxyalkyl bonded silica support. The mechanism of separation appears to be dependent on hydrodynamic radius, hydrophobic and ionic interactions. Support for this contention is based on the chromatographic properties of these peptides and proteins at different mobile phase ionic strengths and pH, oxidation state of amino acid residues and total hydrophobicity of the peptide or protein. This column is also capable of separating native angiotensin-I from its iodinated congener. Recoveries of proteins and peptides from this column ranged between 70-100%. Unlike typical reverse phase separations, this modified silica chromatographic media allows for an alternative technique employing aqueous eluents for rapid separation/isolation and purification of peptides and proteins from natural or synthetic sources.