New affinity chromatography matrices for glycomacropeptide purification from cheese whey

MARÍA F. BAIELI; NICOLAS URTASUN; OSVALDO CASCONE; FEDERICO J. WOLMAN

Mar del Plata

Congreso; VIII Encuentro Latinoamericano y del Caribe de Biotecnología; 2013

REDBIO Argentina Asociación Civil

The aim of this work was the development of a novel affinity chromatographic matrix for glycomacropeptide (GMP) purification from cheese whey. Matrices consisted of chitosan mini-spheres with wheat germ agglutinin (WGA) immobilized as the affinity ligand. The development was based on the affinity of WGA for sialic acid and N-acetyl glucosamine, a monomer present in the chitosan molecule. GMP has high levels of sialic acid (7-8%), so WGA can be an appropriate ligand for GMP direct isolation. GMP is rich in threonine residues. Its removal from whey will leave remnant whey reduced in this amino acid, which is important because high threonine levels in milk formulae bring about an inadequate brain development in infants. Matrices did not show a significant binding of GMP at pH 4 and 5. At pH 7 and 8.5 adsorption was similar. The maximum adsorption capacities at pH 7 were between 137.0 and 96.6 mg/g and at pH 8.5 were between 149.4 and 95.5 mg/g depending on the ligand density. the matrices showed full GMP adsorption from whey, allowing its depletion. Therefore, the developed matrices are promising application for GMP purification from whey, increasing its added value and allowing its use for infant milk formulations.