Purification and characterization of an ommin-binding protein from an acid-methanol extract of diapause eggs of the silkworm, Bombyx mori

摘要

An ommin-binding protein (OMBP) in the acid-methanol extract of diapause eggs of the silkworm, Bombyx mori was found. OMBP was purified by a modification of the purification method for ommin, and the molecular mass of OMBP was 32 kDa by SDS-PAGE. The purified protein was similar to a kind of 30-kDa protein that is known to be a major plasma protein in the larval hemolymph on the basis of immunochemical reactivity. The changes of OMBP during two days after oviposition was compared with diapause eggsand non-diapause eggs by the Western blot analysis using anti-OMBP antiserum, but there were no differences in the immuno positive signals. OMBP was recognized just before hatching, but disappeared after hatching. However, the immuno positive signal wasfound in the larvae after hatching using anti-30-kDa protein antiserum. According to the results, OMBP seems to be similar to a strand of 30-kDa protein found during the egg stages, but OMBP is different from 30-kDa proteins in the larvae after hatching. The relationship between 30-kDa proteins and OMBP in the eggs of the silkworm is discussed.