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

Proteins were extracted from the cuticle of mid-instar pupae of Tenebrio molitor 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 period deposits cuticular proteins different from those deposited during the pre-ecdysial period. The complete amino acid sequence was determined for four of the urea-extractable proteins from Tenebrio mid-instar 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. (C) 1998 Elsevier Science Ltd. All rights reserved.