Rational protein design to improve the thermal stability of a Bacillus thuringiensis Vip3A protein
Issued Date
2025-11-01
Resource Type
ISSN
00222011
eISSN
10960805
Scopus ID
2-s2.0-105013271014
Journal Title
Journal of Invertebrate Pathology
Volume
213
Rights Holder(s)
SCOPUS
Bibliographic Citation
Journal of Invertebrate Pathology Vol.213 (2025)
Suggested Citation
Kunlawatwimon T., Promdonkoy B., Boonserm P. Rational protein design to improve the thermal stability of a Bacillus thuringiensis Vip3A protein. Journal of Invertebrate Pathology Vol.213 (2025). doi:10.1016/j.jip.2025.108429 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/111760
Title
Rational protein design to improve the thermal stability of a Bacillus thuringiensis Vip3A protein
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Corresponding Author(s)
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Abstract
Vip3A proteins produced by the Bacillus thuringiensis bacterium exhibit insecticidal activity against various crop-damaging lepidopteran pests. However, their limited thermal stability and short shelf life render them unsuitable for use as biopesticides. In this study, we employed rational protein design to enhance the thermal stability of Vip3A64 while minimizing its negative impact on insecticidal activity. This involves substituting potential amino acids based on structural data and using a computational tool (HoTMuSiC) to predict the effect of mutations on the protein's thermal stability as defined by the melting temperature (Tm). We then introduced eight single amino acid substitutions (V239T, V320K, A351C, A351F, D621I, N633Y, E754W, and Q771I) into the tetrameric core and solvent-exposed domains of Vip3Aa64. As determined by the protein thermal shift (PTS) assays, the N633Y and V239T mutants exhibit higher protein melting temperatures than those of the wild type, indicating their enhanced thermal stability. In contrast to other mutants, V239T and N633Y retained their insecticidal activity after one hour of exposure to the high temperature of 55 ˚C. Furthermore, after one month of storage at 37 ˚C, N633Y was the only mutant capable of killing Spodoptera exigua larvae, indicating that it is more stable than the other mutants and the wild type. This study highlights the potential of rational protein design to improve thermal stability and provides a framework for developing effective insecticidal proteins for sustainable agriculture.