Isolation and purification of lactoferrin from cationic proteins of goat polymorphonuclear cells

Polymorphonuclear (PMN) cells of ruminants possess huge number of large granules endowed with different cationic proteins and peptides like myeloperoxidase, elastase, acid and alkaline phosphatase, lysozyme, lactoferrin. Theses granules from goat PMN cells were extracted by differential centrifugation. The cationic proteins present in granules were resolved by acetic acid-urea polyacrylamide gel electrophoresis (AU-PAGE) and molecular weight determined using 12% SDS-PAGE. The specificity of isolated lactoferrin, both by agarose double immunodiffusion and western blotting using anti-lactoferrin IgG raised in rabbit against standard bovine lactoferrin indicated that goat lactoferrin is homologous to bovine milk lactoferrin. Sodium dodecyl sulphate-PAGE analysis revealed that the purified protein had a molecular weight of about 80 kilo dalton. Using single step purification method by heparin-affinity chromatography, lactoferrin was purified from acid extract of PMN cells granules.