López-Giraldo Estefanía, Carrillo Elisa, Titaux-Delgado Gustavo, Cano-Sánchez Patricia, Colorado Alland, Possani Lourival D, Río-Portilla Federico Del
Instituto de Química, Universidad Nacional Autónoma de México, CdMx, Mexico.
Center for Membrane Biology, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, TX, USA.
Toxicon. 2023 Jan 15;222:106985. doi: 10.1016/j.toxicon.2022.106985. Epub 2022 Nov 24.
Scorpine is an antimicrobial and antimalarial peptide isolated from Pandinus imperator scorpion venom. As there are few functional and structural studies reported on scorpine-like peptides, we investigated the recombinant truncated N- and C-terminal domains as well as complete scorpine using biological assays and determined the N- and C-terminal structures using solution nuclear magnetic resonance. The study was conducted using recombinant N- and C-terminal peptides and complete scorpine expressed in Escherichia coli. The results showed that N-scorpine presented a random coil structure in water and adopted α-helical folding in the presence of 50% trifluoroethanol (TFE). C-scorpine contains three disulfide bonds with two structural domains: an unstructured N-terminal domain in water that can form a typical secondary alpha-helix structure in 50% TFE and a C-terminal domain with the CS-αβ motif. Our findings demonstrate cytolytic activity associated with C-scorpine, N-scorpine, and scorpine, as well as channel blocking activity associated with the C-scorpine domain.
蝎毒素是一种从帝王蝎毒液中分离出来的抗菌和抗疟肽。由于关于类蝎毒素肽的功能和结构研究报道较少，我们使用生物学测定法研究了重组截短的N端和C端结构域以及完整的蝎毒素，并使用溶液核磁共振确定了N端和C端结构。该研究使用了在大肠杆菌中表达的重组N端和C端肽以及完整的蝎毒素。结果表明，N端蝎毒素在水中呈现无规卷曲结构，在50%三氟乙醇（TFE）存在下形成α-螺旋折叠。C端蝎毒素含有三个二硫键，有两个结构域：在水中无结构的N端结构域，在50% TFE中可形成典型的二级α-螺旋结构，以及具有CS-αβ基序的C端结构域。我们的研究结果表明，C端蝎毒素、N端蝎毒素和蝎毒素具有溶细胞活性，以及与C端蝎毒素结构域相关的通道阻断活性。
