Abstract
This study was carried out to separate immunoglobulin G(IgG) from colostrum using reverse micellar extraction of cationic surfactant and to suggest suitable extraction conditions. The reconstituted colostrum powder was solubilized into a reverse micellar phase containing CDAB(cetyldimethylethyl ammonium bromide) by mixing equal volume of the aqueous and organic phase with constant stirring. The solubilization of proteins from the aqueous to the organic phase was manipulated by pH and ionic strength of the aqueous phase and concentration of surfactant in the organic phase. Based on the SDS-PAGE and densitometry, about more than 90% of initial IgG was remained in the aqueous phase after reverse micellar extraction. Although the aqueous phase contained lactoferrin and bovine serum albumin as minor components, about 93% of the total protein was IgG. The efficient extraction was achieved by the reaction of sodium phosphate buffer(pH 8) containing 50 mM KCl and organic phase containing 100 mM CDAB. The separation of IgG using reverse micellar extraction was simple, highly efficient and easy to be scaled up.
본 연구에서는 역미셀을 이용한 단백질 추출공정에서 적극적으로 활용되지 못했던 양이온 계면활성제에 의한 단백질 추출 가능성을 제시하였으며 초유로부터 IgG의 분리를 위한 반응조건을 조사하였다. IgG의 분리에 적합한 조건은 반응 수용액상의 경우 pH 8, 50 mM KCl었으며 유기용매상의 계면활성제(CDAB) 농도는 100 mM로 나타났다. 위의 조건에서는 초기시료에 존재하는 IgG의 90%이상이 회수되었으며 회수된 단백질의 93%가 IgG로 나타났다. 또한 본 연구는 기존의 역미셀을 이용한 일반적인 단백질 추출공정인 정추출 및 역추출 공정을 이용하지 않고 정추출 공정만을 이용함으로써 추출과정을 단순화하였다.
