2 research outputs found
Far-Field Electrostatic Signatures of Macromolecular 3D Conformation
In solution as in vacuum, the electrostatic field distribution
in the vicinity of a charged object carries information on its three-dimensional
geometry. We report on an experimental study exploring the effect
of molecular shape on long-range electrostatic interactions in solution.
Working with DNA nanostructures carrying approximately equal amounts
of total charge but each in a different three-dimensional conformation,
we demonstrate that the geometry of the distribution of charge in
a molecule has substantial impact on its electrical interactions.
For instance, a tetrahedral structure, which is the most compact distribution
of charge we tested, can create a far-field effect that is effectively
identical to that of a rod-shaped molecule carrying half the amount
of total structural charge. Our experiments demonstrate that escape-time
electrometry (ETe) furnishes a rapid and facile method
to screen and identify 3D conformations of charged biomolecules or
molecular complexes in solution
Reproducibility of fluorescent expression from engineered biological constructs in E. coli
We present results of the first large-scale interlaboratory study carried out in synthetic biology, as part of the 2014 and 2015 International Genetically Engineered Machine (iGEM) competitions. Participants at 88 institutions around the world measured fluorescence from three engineered constitutive constructs in E. coli. Few participants were able to measure absolute fluorescence, so data was analyzed in terms of ratios. Precision was strongly related to fluorescent strength, ranging from 1.54-fold standard deviation for the ratio between strong promoters to 5.75-fold for the ratio between the strongest and weakest promoter, and while host strain did not affect expression ratios, choice of instrument did. This result shows that high quantitative precision and reproducibility of results is possible, while at the same time indicating areas needing improved laboratory practices.Peer reviewe