[Molecular biological analysis of house dust mite allergens]

Using a host-vector system of Escherichia coli, we could produce one of major house dust mite allergens, Der f II in large quantity for therapeutic and diagnostic purposes. About 5 mg of purified and biologically active rDer f II was obtained from one liter culture, which was corresponding to the amount in about 30 g of live mite. The rDer f II was almost identical with native Der f II with respects to biological and physicochemical view points. Native mite Der f II is a mixture of several kinds of Der f II molecule with a few amino acid substitutions, which were due to polymorphisms among individual mite gene sequence. We had cloned three kinds of Der f II cDNAs from mite culture and expressed in E. coli and prepared three kinds of rDer f II in this system. As a result of comparison of IgE binding activity among three rDer f IIs and nDer f II, there was no significant difference observed.