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Mechanical denaturation : forced unfolding of proteins Li, Yongnan
Abstract
Mechanical denaturation has emerged as a novel method to study chemical and physical properties of protein molecules. In this thesis, single-molecule force spectroscopy has been carried out using the atomic force microscope to investigate the mechanical design of proteins through denaturation via an applied mechanical force. In the first study, a small globular protein has been shown to exhibit pronounced anisotropic response to directional mechanical stress. One protein can be both mechanically strong and weak. It will be strong when direction of the force vector is aligned with particular structural elements of the protein, and it will be weak otherwise. Mechanical denaturation in the strong direction is accompanied by cooperative disruption of intramolecular interactions in the protein. Conversely, mechanical denaturation in the weak direction is accompanied by sequential disruption of those same interactions. In the second study, the mechanical properties of a cofactor dependent protein is characterized. It is shown that both the protein and cofactor are mechanically strong in the presence of the cofactor. Removal of the cofactor tremendously diminishes the mechanical strength of the protein. The mutually supportive roles of structure and function are demonstrated through mechanical denaturation experiments.
Item Metadata
Title |
Mechanical denaturation : forced unfolding of proteins
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
2013
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Description |
Mechanical denaturation has emerged as a novel method to study chemical and
physical properties of protein molecules. In this thesis, single-molecule force
spectroscopy has been carried out using the atomic force microscope to investigate
the mechanical design of proteins through denaturation via an applied mechanical
force. In the first study, a small globular protein has been shown to exhibit
pronounced anisotropic response to directional mechanical stress. One protein
can be both mechanically strong and weak. It will be strong when direction of
the force vector is aligned with particular structural elements of the protein, and
it will be weak otherwise. Mechanical denaturation in the strong direction is accompanied
by cooperative disruption of intramolecular interactions in the protein.
Conversely, mechanical denaturation in the weak direction is accompanied by sequential
disruption of those same interactions. In the second study, the mechanical
properties of a cofactor dependent protein is characterized. It is shown that both
the protein and cofactor are mechanically strong in the presence of the cofactor.
Removal of the cofactor tremendously diminishes the mechanical strength of the
protein. The mutually supportive roles of structure and function are demonstrated
through mechanical denaturation experiments.
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Genre | |
Type | |
Language |
eng
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Date Available |
2013-04-09
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Provider |
Vancouver : University of British Columbia Library
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Rights |
Attribution-NonCommercial-NoDerivs 3.0 Unported
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DOI |
10.14288/1.0073778
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
2013-05
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Campus | |
Scholarly Level |
Graduate
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Rights URI | |
Aggregated Source Repository |
DSpace
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Rights
Attribution-NonCommercial-NoDerivs 3.0 Unported