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    Análisis estructural y determinación de la actividad tóxica de las mutantes 8cry11l553f, 8cry11l556w, y 8cry11l553f-l556w obtenidas por mutagénesis sitio dirigida en larvas de primer estadio de aedes aegypti.
    (Bucaramanga : Universidad de Santander, 2018, 2018-11-23) Herrera Pineda, Diego Fernando; Suárez Barrera, Miguel Orlando; Rueda Forero, Nohora Juliana
    Bacillus thuringiensis is a Gram-positive bacterium, δ-endotoxins producer that are toxic to different orders of insects and nematodes. Cry11 is a specific toxin against the vector A. aegypti, which is responsible for the transmission of dengue, zika and chikungunya; however, its mode of action and structure-function characteristics have not yet been fully elucidated. The research group of Molecular Biology and Biotechnology of the UDES, has a library obtained by shuffling the DNA of cry11 genes, highlighting the variant 8Cry11, which is 6 times more toxic than Cry11Aa and 3.8 more than Cry11Bb. Molecular Docking studies showed that positions 553 and 556 of this protein are relevant in the interaction with the cadherin receptor, to corroborate this information, site-directed mutagenesis was performed to reverse the aforementioned mutations, obtaining the variants 8Cry11L553F, 8Cry11L556W, and 8Cry11L553F-L556W. In this work, the toxic activity of mutants 8Cry11L553F, 8Cry11L556W, and 8Cry11L553F-L556W was determined, as well as an approximation of protein analysis both in silico and in vitro through SDS-PAGE. To achieve this, the ideal conditions for the production of δ-endotoxin (Cry11Aa) were standardized, finding a relationship between glucose concentrations (15g / L) and sources of organic and inorganic nitrogen in a ratio of 3: 7; the production of protoxin (~ 100 kDa) and toxin (32 and 34 kDa) was corroborated by SDS page. To determine the mean lethal concentration in comparison with the mutant 8Cry11 and the parental Cry11Aa, the toxicity of the mutants was evaluated, against first stage larvae of A. aegypti. The results showed loss of toxicity for the variants under study, which indicated that substituted amino acids in domain III were strongly possible involved in the loss of toxicity due to structural features.