Isolation of beta-lactoglobulin from cow milk

Abstract DOI http://dx.doi.org/10.13070/rs.en.1.877 Date 2014-06-10 Cite as Research 2014;1:877 License CC-BY Isolation of beta-lactoglobulin from cow milk Bolor Buyanbadrakh 1 (bolor at hsum-ac dot mn), Munkhtsetseg Janlav 1 , Namsrai Javkhlantugs 21 School of Pharmaceutical and Biomedical Science, Mongolian National University of Medical Sciences, Ulaanbaatar, Mongolia. 2 School ofChemistry and Chemical Engineering, National University of Mongolia, Ulaanbaatar, Mongolia A simple and inexpensive procedure by combining ion exchange chromatography and gel filtrationchromatography is introduced to purify bovine β-lactoglobulin (β–Lg). Bovine whey protein sample in Trisbufferwas firsted depleted of casein and fat, adsorbed on DEAE-Sepharose FF packed column, eluted with lineargradient of NaCl, and further purified with Sephadex G-75 gel. The purity of bovine β–Lg is checked by SDS-PAGE. INTRODUCTION Cow milk is the most common source of essential amino acids and functional proteins in human diet. However thereare increased incidences of allergic reactions to more than 20 milk proteins. One of the most important allergens inmilk is β-lactoglobulin (β-lg) to which about 82% of milk allergic patients are sensitive [1]. To better understanding ofthe underlying mechanism of allergic reaction has always necessitated studying antigenic and molecularcharacteristics of allergen, thus it is important to obtain the antigens in pure form [2]. In addition, purified antigens willallow clinical researchers to determine specific antibodies using ELISA technique [3].β-lactoglobulin is one of major whey protein in bovine milk, constituting approximately 50% of total whey protein [4].Bovine β-lactoglobulin contains 162 amino acids (MW 18.4kDa) and its isoelectric point is 5.3 [5]. The protein isknown for its high value as food ingredients and its functional properties [6] [7] [8].Various techniques have been used to purify β-lactoglobulin from whey protein such as precipitation, membranefiltration and HPLC [9] [10]. The optimum conditions for initially separating the proteins such as β-lactalbumin, β-lg,bovine serum albumin, immunoglobulin G and lactose from a dairy whey mixture could be determined by acommercial anion-exchange resin [11]. In this paper a 2-step method to purify β-lg from whey protein is presented.