Biochemical and Allergenic Properties of the House Dust Mite Extract, Dermatophagoides pteronyssinus

A Further study has been made on the house dust mite extract, Dermatophagoides pteronyssinus , with emphasis on gel-filtrated fraction 2 (F₂). The crude mite extract showed at least nine discs on polyacrylamide disc electrophoresis and contained less than 0.25 % sialic acid and less than 0.5 mM hexosamine and no detectable uronic acid. From gel filtration of the crude extract a No. 2 fraction (F₂) with allergenic activity showed at least five components on SDS disc electrophoresis covering a molecular weight range of between 15,000 and 70,000. The major allergenic activity of F₂ dissolved in pH 7–8 and 4–5 on an isoelectric focusing column. Affinity chromatography of lectins showed that allergenic activity did not relate to structures of N -acetyl-D-glucosamine or N -acetyl-D-galactosamine. Allergenic activity of the crude extract was not affected by peptic digestion and the mite digest prepared by trypsin and pronase showed a similar fraction-action and activity profile as crude extract.