Further application of a two-step heparin affinity chromatography method using divalent cations as eluents: Purification and identification of membrane-bound heparin binding proteins from the mitochondrial fraction of HL-60 cells

Membrane proteins were obtained from the mitochondrial fraction of HL-60 cells by solubilization with octyl glucoside and bound to heparin-gels. Bound proteins were successively eluted with solutions containing increasing concentrations of Mg²⁺ in the first and increasing concentrations of Ca²⁺ in the second chromatography. After SDS-PAGE and subsequent N-terminal amino acid analysis of proteins on each band, 13 proteins were identified. Fifteen out of the 37 proteins analysed were modified at their N-termini. These results show that this two-step affinity chromatography method using divalent cations as eluents can be applied to a variety of membranes for the isolation of specific proteins.