Antibodies raised against a Sunn bug (Eurygaster integriceps Put.) recombinant protease, rGHP3p2, can inhibit gluten‐hydrolyzing activity

Abstract

Sunn pest or Sunn bug, Eurygaster integriceps Put., salivary gland proteases are responsible for the deterioration of wheat flour quality during dough mixing, resulting from gluten hydrolysis. These proteases are highly heterogeneous and show low sensitivity to most types of proteinaceous inhibitors, meaning that such inhibitors cannot be used to prevent gluten damage. The present study describes the generation of a specific peptide antibody, raised against the active center of the recombinant gluten‐hydrolyzing protease (GHP3). The recombinant protein, encoding two repeats of the GHP3 sequence element involved in forming the S4 pocket and binding of substrate at position P4, was designed and expressed in Escherichia coli. The antibodies raised to this recombinant protein showed inhibitory activity against the GHP3 protease. The results indicate that it is possible to design specific antibodies to inhibit wheat‐bug gluten‐hydrolyzing proteases.

Construction of scFv-antibodies to the active center of the Sunn bug (Eurygaster integriceps Put) gluten-hydrolyzing protease GHP3

“…These constructs allows potential creation of transgenic plants that are resistant to grain damage caused by E. integriceps. Extraction of total RNA from the spleen of mice immunized by chimeric protein consisting of fragments of GHP3 active center [2] and cDNA synthesis were performed with Trizol reagent and oligo-dT primers. PCR amplification of the entire variety of variable fragments of heavy (VH) and light (VL) chains of murine IgG was performed using 22 pairs of specially selected primers (Progen).…”

“…To express the selected scFv fragments in bacteria E. coli, their genes were re-cloned from pSEX81 into pOPE101 expression vector. Previously, the data of structure analysis of the GHP3 proteinase of E. integriceps [1] were used to design and synthesize the chimeric gene encoding several copies of polypeptide chain involved in the formation of the active center of the protein [2]. The recombinant product overexpressed in E. coli was used to immunize mice, and B-cells (mouse spleen) were isolated after four cycles of immunization, which allow us to obtain mRNA from these cells.…”