Impacto de la conformación y la estabilidad en la tendencia a la agregación : el caso de una familia de proteínas todo-ß

?98? and ?78? are two all-ß variants of IFABP (intestinal fatty acid binding protein). These frameworks became useful for studying the molecular determinants related to aggregation of ß barrel proteins. Albeit displaying increased conformational plasticity, these variants exhibit a native-like ß bar...

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Autor principal: Angelani, Carla Romina
Otros Autores: Curto, Lucrecia María
Formato: Tesis doctoral acceptedVersion
Lenguaje:Español
Publicado: Facultad de Farmacia y Bioquímica 2017
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Acceso en línea:http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=posgraafa&cl=CL1&d=HWA_1961
http://repositoriouba.sisbi.uba.ar/gsdl/collect/posgraafa/index/assoc/HWA_1961.dir/1961.PDF
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Sumario:?98? and ?78? are two all-ß variants of IFABP (intestinal fatty acid binding protein). These frameworks became useful for studying the molecular determinants related to aggregation of ß barrel proteins. Albeit displaying increased conformational plasticity, these variants exhibit a native-like ß barrel topology and are able to support a cooperative folding behavior. This thesis work explores the conformation, stability and amyloidogenic tendency of these proteins. We chose 2,2,2 trifluoroethanol (TFE) as the aggregation triggering agent, investigating the kinetic mechanism and the morphological characteristics of the amyloid aggregates. We also evaluated the impact of low concentrations of TFE (< 15 % v/v) ? a condition where the protein remains soluble - on conformation and stability using various biophysical techniques. These studies revealed the conformational coalescence of the three proteins and allowed to refine the structural model proposed for the abbreviated variants. Finally, in order to address the early events leading to the formation of the aggregation nucleus, we studied the changes occurring immediately after the addition of 25 % v/v TFE. We concluded that the structural change achieved at 10 % v/v TFE would mimic the events necessary to trigger aggregation.