Sequence studies on post-ecdysial cuticular proteins from pupae of the yellow mealworm, Tenebrio molitor

Abstract

Proteins were extracted from the cuticle mid-instar pupae of Tenebrio and purified by column chromatography. The protein pattern obtained by two-dimensional gel-electrophoresis was different from that obtained from pharate pupal cuticle, indicating that Tenebrio during the post-ecdysial pupal deposits cuticular proteins different from those deposited during the preecdysial period. The complete amino acid sequence was determined for four of the urea-extractable proteins from Tenebrio midinstar pupal cuticle. They range from 5.8 to 16.7 kDa in molecular weights and from 5.2 to 7.9 in isoelectric points. Little similarity was observed between the sequenced post-and pre-ecdysial cuticular proteins from Tenebrio pupae. Only one of the sequenced post-ecdysial proteins contains the Ala-Ala-Pro-Ala/Val motif common in proteins from Tenebrio larval/pupal pharate cuticle and from locust pharate cuticle. None of the post-ecdysial proteins contains the conserved hydrophilic sequence regions described for Tenebrio pharate cuticular proteins.