Expression and purification of recombinant Lopap from Lonomia obliqua (Lepidoptera: Saturniidae) in Spodoptera frugiperda larvae using the baculovirus system

Abstract

A process using Spodoptera frugiperda larvae as biological factories for the expression and one-step purification of the Lonomia obliqua prothrombin activator protein (Lopap) is described. Two recombinant Lopap (Lp) variants were designed, each carrying a polyhistidine tag at different positions: C-terminal (LpHis) or N-terminal (HisLp). The highest yield was obtained for LpHis (95.4 μg per gram of S. frugiperda larvae), and both toxins were purified by immobilized metal-ion affinity chromatography (IMAC) to high purity. Both recombinant toxins were recognized by the antilonomic serum, an antivenom used to treat lonomism, produced by the Butantan Institute (São Paulo, Brazil). Notably, although the C-terminal His-tag reduced the biological (procoagulant) activity of LpHis, the protein remained immunogenic. Beyond its potential as an immunogen, recombinant Lopap may also serve as a tool for therapeutic or diagnostic applications, expanding its relevance beyond antivenom development. This study reports the first use of a baculovirus–insect larval expression system to produce recombinant proteins from L. obliqua, providing a versatile platform for future biotechnological innovations.