Isolation and purification of beta-lactoglobulin from cow milk
Ranjit Aich1, Subhasis Batabyal2, Siddhartha Narayan Joardar3
1Department of Veterinary Biochemistry, Faculty of Veterinary and Animal Sciences, West Bengal University of Animal and Fishery Sciences, Belgachia - 700 037, Kolkata, India; Department of Veterinary Biochemistry, College of Veterinary Science and Animal Husbandry, Mhow - 453 446, Madhya Pradesh, India.
Aim:
The present study was undertaken to standardize a convenient method for isolation and purification of β-lactoglobulin (β-lg) from cow milk keeping its antigenicity intact, so that the purified β-lg can be used for detection of cow milk protein intolerance (CMPI).
Materials And Methods:
Raw milk was collected from Gir breed of cattle reared in Haringhata Farm, West Bengal. Milk was then converted to skimmed milk by removing fat globules and casein protein was removed by acidification to pH 4.6 by adding 3 M HCl. β-lg was isolated by gel filtration chromatography using Sephacryl S-200 from the supernatant whey protein fraction. Further, β-lg was purified by anion-exchange chromatography in diethylaminoethyl-sepharose. Molecular weight of the purified cattle β-lg was determined by 15 percent one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was analyzed by gel documentation system using standard molecular weight marker.
Results:
The molecular weight of the purified cattle β-lg was detected as 17.44 kDa. The isolated β-lg was almost in pure form as the molecular weight of purified β-lg monomer is 18kDa.
Conclusion:
The study revealed a simple and suitable method for isolation of β-lg from whey protein in pure form which may be used for detection of CMPI.
