Amino acid substitution on β1 and αF of Cyt2Aa2 affects molecular interaction of protoxin

BMB Reports

Siriya Thammachat^1¹  Nuanwan Pungtanom^1² 

[1] Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Phuttamonthon 4 Road, Salaya, Nakhon Pathom 73170, Thailand^1;National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Phaholyothin Road, Klong 1, Klong Luang, Pathum Thani 12120, Thailand^2

关键词: Bacillus thuringiensis;   

DOI  :  

学科分类：生物化学/生物物理

来源: Korean Society for Biochemistry and Molecular Biology

【 摘 要 】

Cyt2Aa2 is a mosquito-larvicidal protein produced as a 29 kDa crystalline protoxin from Bacillus thuringiensis subsp. darmstadiensis. To become an active toxin, proteolytic processing is required to remove amino acids from its N- and C-termini. This study aims to investigate the functional role of amino acid residues on the N-terminal Beta1 and C-terminal alphaF of Cyt2Aa2 protoxin. Mutant protoxins were constructed, characterized and compared to the wild type Cyt2Aa2. Protein expression data and SDS-PAGE analysis revealed that substitution at leucine- 33 (L33) of Beta1 has a critical effect on dimer formation and structural stability against proteases. In addition, amino acids N230 and I233-F237 around the C-terminus alphaF demonstrated a crucial role in protecting the protoxin from proteolytic digestion. These results suggested that Beta1 and alphaF on the Nand C-terminal ends of Cyt2Aa2 protoxin play an important role in the molecular interaction and in maintaining the structural stability of the protoxin.

【 授权许可】

Unknown