รองศาสตราจารย์ ดร.ปนัดดา บุญเสริม

Our current research focuses on the structure and function studies of the insecticidal proteins produced from Gram-positive bacteria. One of the family of insecticidal proteins is the binary toxin, consisting of BinA and BinB subunits, from Lysinibacillus sphaericus, which is currently used as an environmentally friendly biopesticide against mosquito vectors of various tropical diseases.  Another novel family of insecticidal proteins is  Vip3Aa, which is secreted during vegetative stage of Bacillus thuringiensis. This toxin is active against lepidopteran insects especially Spodoptera exigua (beet armyworm) and Spodoptera litura (tobacco cutworm), both of which are major pests of many important crops of Thailand.   Over the past decade, collective findings have been produced from our laboratory, however, some critical information is still missing especially the structural information of these insecticidal proteins.  To elucidate the molecular basis of the cytotoxicity, we have been the first to solve the three-dimensional structure of the active form of the BinB subunit. Together with the structural analysis, functional assays have been carried out in search of the critical amino acids for the toxicity and specificity of these insecticidal proteins. We also investigate the cellular responses during the intoxication process such as the intracellular trafficking, apoptosis and the ultrastructural alterations inside the insect-larval cells. Altogether, the comprehensive structural and functional analyses will facilitate the development of the insecticidal proteins to enhance the potency, expand the insect specificity and prevent the development of insect resistance.

Selected Publications

1. Tangsongcharoen C, Jupatanakul N, Promdonkoy B, Dimopoulos G, Boonserm P. Molecular analysis of Culex quinquefasciatus larvae responses to Lysinibacillus sphaericus Bin toxin. PLoS ONE. 2017; 12(4):e0175473.
2. Kunthic T, Surya W, Promdonkoy B, Torres J, Boonserm P. Conditions for homogeneous preparation of stable monomeric and oligomeric forms of activated Vip3A toxin from Bacillus thuringiensis. Eur Biophys J. 2017; 46(3):257–264.
3. Surya W, Chooduang S, Choong YK, Torres J, Boonserm P. Binary toxin subunits of Lysinibacillus sphaericus are monomeric and form heterodimers after in vitro activation. PLoS One. 2016; 11(6):e0158356. 
4. Chimnaronk S, Sitthiroongruang J, Srisucharitpanit K, Srisaisup M, Ketterman AJ, Boonserm P. The crystal structure of JNK from Drosophila melanogaster reveals an evolutionarily conserved topology with that of mammalian JNK proteins. BMC Structural Biology. 2015; 16,15(1):17.
5. Lekakarn H, Promdonkoy B, Boonserm P. Interaction of Lysinibacillus sphaericus binary toxin with mosquito larval gut cells: binding and internalization. J Invertebr Pathol. 2015; 132: 125-131.
6. Tangsongcharoen C, Chomanee N, Promdonkoy B, Boonserm P. Lysinibacillus sphaericus binary toxin induces apoptosis in susceptible Culex quinquefasciatus larvae. J Invertebr Pathol. 2015; 128:57-63. 
7. Srisucharitpanit K, Yao M, Chimnaronk S, Promdonkoy B, Tanaka I, Boonserm P. Crystal structure of BinB: A receptor binding component of the binary toxin from Lysinibacillus sphaericus. Proteins. 2014; 82(10):2703-12.