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Engineering Approaches to Biomolecular Motors: From in vitro to in vivo Poster Abstracts
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18-POS
Board 18
Dynamics of the Bacterial Flagellar Motor: Theoretical Model and Validation
Jasmine A. Nirody
1
, Richard M. Berry
2
, George Oster
1
.
1
University of California, Berkeley, Berkeley, CA, USA,
2
University of Oxford, Oxford,
Oxfordshire, United Kingdom.
The bacterial flagellar motor (BFM) drives swimming in a wide variety of bacterial species.
Understanding the dynamics of the BFM has a broad range of applications, including drug
design and engineering biosensors because of this motor's fundamental role in a variety of
fundamental biological processes, such as chemotaxis and community formation. We put
forward a model for motor rotation that implicates a steric interaction between the rotor and the
torque-generating complexes (stators). Ours was the first mechanically-specific model of torque
generation in the BFM, pinpointing critical residues and structures for motor function. An
important feature of our model is that motor rotation is loosely coupled to ion flow across the
membrane. As a consequence, we predict that the maximum speed of the motor increases as
additional stators are recruited to the motor. While this is contrary to the current widely-held
belief that there is a universal upper limit to the speed of the BFM, we show that this is
consistent with current experimental evidence. We also put forward several further experiments
and measurements designed to test the validity of this model and its implications.
20-POS
Board 20
Influence of Net Charge Value on the Second Virial Coefficients of BSA Solutions
YoonKook Park
, J. W. Park.
Hongik University, Sejong, South Korea.
Using a Wescor colloidal membrane osmometer the osmotic pressures of bovine serum albumin
(BSA) aqueous solutions were measured under two different salts of ammonium sulfate and
potassium sulfate. The experimental osmotic pressure made it possible to estimate the osmotic
virial coefficient for BSA. The type of cation with same anion, pH, and ionic strength played a
significant role in forces between protein molecules. The magnitude of the coefficient seems to
be affected by the net charge value of the BSA and depth of the square well.