Molecular chaperones Chemical Engineering Protein Engineering
Chaperonins are a class of cage-like molecular machines that assist the folding of polypeptides by binding and releasing non-native substrates into their inner cavity, where sequestered from the medium the substrate can fold to its native state. The main goal of this work is to understand the structure-function relationship of chaperonin. Here we study two major aspects of this relationship: (1) thermodynamics of protein folding inside the chaperonin cavity and (2) conformational changes of the E. coli chaperonin GroEL in its reaction cycle. We have studied the thermodynamics of protein folding, confined in the chaperonin cavity using the simple HP model of protein undergoing the coil-to-globule transition. Using the Wang-Landau method we have quantified the increase in thermal stability of a native state in a spherical confining geometry, measured as an increase in melting temperature with decreasing radius of confining sphere. We are the first to show that the t [right arrow] r transition in GroEL subunit occurs spontaneously using unbiased molecular dynamics simulation. The transition pathway is shown to lie along low frequency quasi-harmonic modes of vibration. We are also the first to observe the spontaneous insertion of Ala480 into the empty nucleotide binding pocket, required for negative interring cooperativity.
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Details
Title
Molecular simulations of chaperonins
Creators
Yelena R. Sliozberg - DU
Contributors
Cameron F. Abrams (Advisor) - Drexel University (1970-)
Awarding Institution
Drexel University
Degree Awarded
Doctor of Philosophy (Ph.D.)
Publisher
Drexel University; Philadelphia, Pennsylvania
Resource Type
Dissertation
Language
English
Academic Unit
Chemical (and Biological) Engineering [Historical]; College of Engineering (1970-2026); Drexel University