• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.438-443
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• 1999

A livetin solution(LS) containing yolk immunoglobulins(IgY) was separated by treating the egg yolk with natural gum, carrageenan. Carrageenan has been used as a food ingredient. Relative absorbance of IgY LS after proteolysis was investigated. IgY LS was fairly stable to pepsin digestion at pH 3.0. However, IgY LS appeared to be susceptible to pepsin digestion at pH 2.0, showing 18% of relative absorbance and complete breakdown H chain after 30 min exposure. Relative absorbance of IgY LS was considerably high after exposure to trypsin and chymotrypsin for 8 hr. IgY LS showed especially good stability to chymotrypsin digestion.

• KSBB Journal
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• v.14 no.6
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• pp.677-681
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• 1999

Purificationi of egg yolk immunoglobulin(IgY) was performed to understand the property of egg immunoglobulin. IgY differs from mammalian IgY in the molecular size(larger), isoelectric point(more acidic), and binding ability with mammalian complement and protein A(nonbinding ability). IgY is also known as ${\gamma}$-livetin and exists in egg yolk together with other two water-solubel proteins, ${\alpha}$-livetin(chicken serum albumin) and ${\beta}$-livetin(${\alpha}_2$-glycoprotein) and various lipoproteins(Low density lipoprotein, LDL and High density lipoprotein, HDL) which are the major components of egg yolk. The first step of isolation of IgY is to separate the water-solube proteins from lipoproteins. We report a simple method for separation of water soluble proteins using k-carrageenan and sedimentation. k-carrageenan was found to be effective for removal of yolk lipoprotein as a precipitate. IgY remained supernatant, and was isolated by chromatography on columns of DEAE-Sephacel and G 75 gel filtration chromatography.