Título
Estudios de la cooperatividad entre proteínas motoras y los efectos de estabilizar microtúbulos con glutaraldehído
Autor
ALMA ROSA OAXACA CAMACHO
Colaborador
BRAULIO GUTIERREZ MEDINA (Director)
Nivel de Acceso
Acceso Abierto
Materias
Resumen o descripción
"En esta tesis se estudio la cooperatividad entre proteinas motoras y los efectos sobre la funcionalidad de microtúbos al estabilizarlos con glutaraldehido. La cinesina es un motor molecular biológico de tamaño nanométrico que convierte la energia quimica de la hidrólisis de ATP en trabajo mecánico. En la célula, la cinesina partcipa en el trasporte intracelular, frecuentemente en grupos, llevando organelos o vesiculas hacia el extremo más(+) de filamentos celulares conocidos como microtúbulos. Por otra parte,existen propuestas de aplicacciones nanotecnológicas basadas en conjuntos de cinesinas trasportando nanotecnologias a lo largo del microtúbulo. Por estas razones, es necesario: 1) Comprender cómo coopera entre si un conjunto de cinesinas y 2) Estabilizar a los microtúbulos basadas en peridos prolongados. Realizar estos estudios son los objetivos de esta tesis, empleando ensayos de motilidad in-vitro en los que cinesinas unidas a una esfera de poliestireno se desplazan sobre microtúbulos fijos sobre una superficie. Utilizando un sistema de pinzas ópticas es posible medir desplazamientos y fuerzas desarrolladas por la cinesina."
"In this thesis, the cooperativity between a motor protein and the stabilizing effects of the microtubule glutaraldehyde has been studied. Kinesin is a biological molecular motor of the nano scale that has a function of converting chemical energy from ATP hydrolysis into mechanical work. This molecular motor is involved in intracellular transport of cargo such as clusters, organelles or vesicles, leading them to the periphery of the cell through filaments called microtubules. Moreover, there have been proposals of nanotechnological applications for kinesin to carry specific nanoparticles along microtubules. With these reasons in mind, it is necessary to first: 1) Understand how group of kinesin motors cooperate with one another as a group and 2) To stabilize microtubules for prolonged periods of time. In this dissertation, we performed these studies using in vitro motility assays in which kinesin was attached to a polystyrene bead and let to stick and move along a fixed microtubule. It is possible to measure the displacements and forces developed by kinesin using an optical tweezers system. Regarding our first experimental goal, measurements were made by varying the number of kinesins per area. It was found that a single kinesin developed forces of 4.5 pN and remained on the microtubule 0.3 s on average, whereas, for sets including more than a single kinesin the force increased up to 5.2 pN and their time of residence was 0.5 s. These results indicate that groups of more than one kinesin do cooperate between each other within the group. In regards to our second goal, we developed a protocol for microtubule stabilization using glutaraldehyde. Microtubules were observed to be stable after several weeks and that proved to be functional, which was checked by kinesin motility assays."
Fecha de publicación
octubre de 2013
Tipo de publicación
Tesis de maestría
Recurso de información
Formato
application/pdf
Idioma
Español
Audiencia
Público en general
Repositorio Orígen
Repositorio IPICYT
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