PRODUCTION OF RECOMBINANT MITE ALLERGEN DER FI IN INSECT CELLS AND CHARACTERIZATION OF PRODUCTS - REMOVAL OF PRO-SEQUENCE IS ESSENTIAL TO IGE-BINDING ACTIVITY

Der fI is a major mite proteinaceous allergen found in house dust. We produced recombinant Der fI (reDer fI) in insect cells using a baculov irus expression system. Based on the molecular mass and N-terminal ami no acid (aa) sequence analysis, reDer fI was found to he comprised of a mixture of two proteins, each of which includes a pro-sequence of di fferent length. The reDer fI had IgE-binding activity at only 20% of t hat of native Der fI. The removal of the pro-sequence in an acidic sol ution drastically increased IgE-binding activity to almost the same as that of native Der fI, showing that the presence of the pro-sequence is inhibitory to the IgE-binding activity of Der fI.