Advances in instrumentation often lead to conceptual breakthroughs. For instance, laser-based optical tweezers led to experiments on the physical forces involved in stretching and binding of biomolecules. The long-term goal of this exploratory program is to provide a new technology for trapping individual biomolecules in aqueous solution, the Anti-Brownian ELectrophoretic trap (ABEL trap). This device will allow trapping of objects 50-100 times smaller than the smallest objects typically trapped with optical tweezers, extending all the way to single proteins and nucleic acids in solution. ? ? The first aim will develop and extend the ABEL trapping concept to enable trapping of individual small, dim biomolecules in buffer, such as a single GFP, a single quantum dot biolabel, and a single molecule of the chaperonin GroEL labeled with only one fluorophore. This will involve reduction of latency by using hardware feedback and optimization of the microfluidic design and surface treatment.
A second aim will develop analysis procedures that will allow extraction of the mobility and diffusion coefficient of the single trapped biomolecule as a function of time. ? ? The ABEL trap will enable extended study of single biomolecules in free solution-a capability which has not previously existed. The ABEL trap directly provides information on the transport properties of the trapped object, such as the occurrence of protein-protein interaction events. In future work, this capability will lead to study of aggregate formation as monomers are added one by one, and eventually the ABEL trap should shed light on the initial events that lead to aggregation and/or misfolding of prions or other proteins in diseases that arise from these abnormalities. ? ? This project will also introduce a new concept into single-biomolecule research: that feedback can be used to cause a single molecule (or small collection of molecules) to violate the Second Law, while preserving the Second Law on the macroscale. The Project Description details the physical, chemical, and biophysical experiments that are required to achieve the main aims; but once the instrumentation is availble to the biomedical community, others will think of experiments that cannot be imagined at the present. It is for this reason that this research represents a new and powerful potential advance for biomedical applications. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21RR023149-03
Application #
7470558
Study Section
Special Emphasis Panel (ZRR1-BT-B (01))
Program Officer
Friedman, Fred K
Project Start
2006-09-01
Project End
2010-07-31
Budget Start
2008-08-01
Budget End
2010-07-31
Support Year
3
Fiscal Year
2008
Total Cost
$180,309
Indirect Cost
Name
Stanford University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
009214214
City
Stanford
State
CA
Country
United States
Zip Code
94305
Wang, Quan; Goldsmith, Randall H; Jiang, Yan et al. (2012) Probing single biomolecules in solution using the anti-Brownian electrokinetic (ABEL) trap. Acc Chem Res 45:1955-64
Bockenhauer, Samuel; Furstenberg, Alexandre; Yao, Xiao Jie et al. (2011) Conformational dynamics of single G protein-coupled receptors in solution. J Phys Chem B 115:13328-38
Wang, Q; Moerner, W E (2010) Optimal strategy for trapping single fluorescent molecules in solution using the ABEL trap. Appl Phys B 99:23-30
Goldsmith, Randall H; Moerner, W E (2010) Watching conformational- and photo-dynamics of single fluorescent proteins in solution. Nat Chem 2:179-86
Cohen, Adam E; Moerner, W E (2008) Controlling Brownian motion of single protein molecules and single fluorophores in aqueous buffer. Opt Express 16:6941-56
Moerner, W E (2007) New directions in single-molecule imaging and analysis. Proc Natl Acad Sci U S A 104:12596-602
Cohen, Adam E; Moerner, W E (2007) Principal-components analysis of shape fluctuations of single DNA molecules. Proc Natl Acad Sci U S A 104:12622-7
Cohen, Adam E; Moerner, W E (2007) Internal mechanical response of a polymer in solution. Phys Rev Lett 98:116001