Yongkuk Lee

Date of Graduation

2014

Document Type

Dissertation

Degree Type

PhD

College

Statler College of Engineering and Mineral Resources

Department

Lane Department of Computer Science and Electrical Engineering

Committee Chair

Parviz Famouri

Committee Co-Chair

Xian-An Cao

Committee Member

Lawrence Hornak

Committee Member

Dimitris Korakakis

Committee Member

Nianqiang Wu

Abstract

A living cell can be considered as a miniaturized device, which carries out complicated tasks such as reproduction, energy conversion and molecule transport. Many cellular functions are highly efficient and mostly performed at nanoscale, which is pursued in fields of Micro total analysis system (&mgr;-TAS) or lab-on-a-chip. Due to unique mechanical functions performing micro/nano transport with high efficiency of the chemo-mechanical energy conversion in cells, motor proteins have been emphasized to perform laboratory functions such as delivery, assembly, detection, and micro/nano-engines. However, several issues ranging from in vitro stability of motor proteins to understanding their functionalities with inorganic materials remain unsolved and continue to hinder the applications of motor proteins. One such issue includes directional control in the motion of motor proteins. Associated filaments are precisely controlled by cellular signals and provide tracks for motor proteins to play critical roles in biological movement and transportation in cells, which is difficult to mimic in vitro..;This study investigates the development of a new methodology for the directional transport of particles using actomyosin. This methodology is applicable to new devices for security, health or environmental applications. The general approach to be developed is based on creating unipolar F-actin arrays on an inorganic substrate. The barbed end of actin filament is anchored on streptavidin-coated surfaces through biotinylated gelsolin. A flow field driven by a mechanical pump is utilized to lay down actin filaments aligned along the direction of the flow. Meanwhile, fascin crosslinks actin filaments to prevent their resuspension. These precisely oriented F-actin arrays provide unidirectional transport of heavy meromyosin-coated particles over distances of several hundred micrometers. In processes of creating unipolar F-actin arrays, blocking solutions are investigated to prevent non-specific binding of F-actin on streptavidin-coated surfaces. Additionally, Ca2+ regulated gelsolin activity with actin filament is investigated in a function of free Ca2+ concentrations.;The advantages of this study are 1) no external regulation and influence is required to guide HMM-coated particles or maintain F-actin arrays, 2) a linear transport of micro/nano particles to desired locations can be accomplished, and 3) patterned tracks of F-actin arrays constructed using micropatterning techniques are available for various applications. This study may provide fundamental understanding of potential roles of myosin II as a nonprocessive motor protein in further applications and may significantly improve the applicability of hybrid devices using biomolecular motor proteins.

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