ISOLATION OF IGA1 FROM HUMAN SERUM BY AFFINITY-CHROMATOGRAPHY USING AN IMMOBILIZED EXTRACT OF THE ALBUMIN GLAND OF HELIX-POMATIA

An extract of the albumin gland of Helix pomatia was linked to Sepharo se-4B and used to prepare IgA from group O human serum; immuno-electro phoresis showed that the preparation was free of Ige and IgM. From stu dies with specific IgA subclass antisera and by comparison with the ac tivity of jacalin-produced material the Helix pomatia extract was foun d to be IgA1 specific. The preparation had red cell anti-A,B specifici ty and was suitable for standardizing and controlling anti-human IgA r eagents. Preparations using six different carbohydrates as eluants inh ibited the agglutination reaction between anti-human IgA and IgA-coate d red cells to varying degrees. The pattern of reactions suggested tha t N-acetyl glucosamine was the IgA binding site for Helix pomatia; thi s differed from its blood group A determinant (N-acetyl galactosamine) which was the same as that for the IgA1 reactive component of jacalin .