Talaga Group
Description
and protein conformational dynamics
732-445-2192
Research
Research Results Archive
September 2006
β-Lactoglobulin Calyx Dynamics
Posted by David Talagaβ-Lactoglobulin Calyx Dynamics
The formation of a hydrophobic core provides a large part of the driving force for protein folding.
We are investigating amyloid formation from β-lactoglobulin and are therefore interested in understanding how the dynamics of core stability are influenced by solution conditions.
We have exploited the presence of a large hydrophobic binding pocket in β-lactoglobulin to encapsulate coumarin 153 (C153).
Steady state spectroscopy reveals a very blue-shifted spectrum consistent with an environment similar to a combination of hexane and toluene.
Time resolved fluorescence Stokes shift measurements reflect the dynamics of the hydrophobic core of β-lactoglobulin.
A transition in the dynamics of the hydrophobic core occurs at a lower temperature than does the melting of the protein as measured by circular dichroism suggesting a partitioning of the enthalpy and entropy balance between the core structure and secondary structure.
Solid-state nanopore measurements of amyloid formation
Posted by David Talaga
In collaboration with the group of Jiali Li at the University of Arkansas Department of Physics we have begun making solid state nanopore electrical measurements on the aggregates that form during assembly of amyloid from ß-lactoglobulin. Our preliminary assessment of the data suggests that the solid state nanopore can distinguish between different classes of amyloid species.
Information theory for 2 color single molecule experiments
Posted by David Talaga
The probability-normalized (∑P(O|S)=1) fluorescence spectra of C153 in hexane (blue) and in methanol (green). The mutual information in bits between the state (polar versus nonpolar) and each photon emitted (red).
From an information theory point of view the molecule encodes information into photons using the dyes as a transducer. The photons are converted into raw data by the detection apparatus and then decoded into a useful form by some data analysis procedure. From the reduced data we draw inferences about the molecule based on the data and our prior knowledge of the system. Two color experiments represent one of the most common types of single molecule fluorescence measurements. We developed a formulation of Shannons information theory to treat two-color problems and showed how it can be used to design experiments based on the number of photons required to deliver a particular amount of information.