Improved purification of beta-lactoglobulin from acid whey by means of ceramic hydroxyapatite chromatography with sodium fluoride as a displacer.
The successful separation of beta-lactoglobulin from other bovine whey proteins was performed by ceramic hydroxyapatite chromatography with a fluoride ion gradient in phosphate buffer as displacement agent. The method was applied to acid whey originating from milk of healthy as well as of mastitic cows. beta-Lactoglobulin was completely eluted in one peak at a fluoride concentration of about 0.6 mol/l. The purity of beta-lactoglobulin in this fraction was at least 96% if whey from healthy milk was processed. Co-eluted contaminants are traces of immunoglobulin G, serum albumin and lactoferrin. In case of mastitic whey the proportion of beta-lactoglobulin is diminished as the amounts of immunglobulin G, serum albumin and lactoferrin are increased within this fraction. Size exclusion chromatography on Superdex 75 pg effectively removed contaminants resulting in a purity for beta-lactoglobulin from normal whey of approximately 99%. The yield of beta-lactoglobulin from physiological whey was 50-55% referring to the fraction highly enriched with beta-lactoglobulin by hydroxyapatite chromatography. In case of mastitic milk the higher amounts of contaminants were also removed successfully by size exclusion chromatography.
Schlatterer
B
B
Institute of Veterinary Biochemistry, Free University of Berlin, Oertzenweg 19b, 14163 Berlin, Germany. bschlatterer@berklin.de
Baeker
R
R
Schlatterer
K
K
D002853:Chromatography, Liquid / Q000379:methods*; D017886:Durapatite; D004591:Electrophoresis, Polyacrylamide Gel; D007782:Lactoglobulins / Q000032:analysis*; D008894:Milk Proteins / Q000737:chemistry*; D012969:Sodium Fluoride / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D000067816:Whey Proteins
D007782:Lactoglobulins; D008894:Milk Proteins; D000067816:Whey Proteins; D012969:Sodium Fluoride; D017886:Durapatite