17 research outputs found
In-cell NMR characterization of the secondary structure populations of a disordered conformation of α-Synuclein within E. coli cells
α-Synuclein is a small protein strongly implicated in the pathogenesis of Parkinsonâs disease and related neurodegenerative disorders. We report here the use of in-cell NMR spectroscopy to observe directly the structure and dynamics of this protein within E. coli cells. To improve the accuracy in the measurement of backbone chemical shifts within crowded in-cell NMR spectra, we have developed a deconvolution method to reduce inhomogeneous line broadening within cellular samples. The resulting chemical shift values were then used to evaluate the distribution of secondary structure populations which, in the absence of stable tertiary contacts, are a most effective way to describe the conformational fluctuations of disordered proteins. The results indicate that, at least within the bacterial cytosol, α-synuclein populates a highly dynamic state that, despite the highly crowded environment, has the same characteristics as the disordered monomeric form observed in aqueous solution
A Thermodynamic Study of Capillary Electrochromatographic Retention of Aromatic Hydrocarbons on a Lauryl Acrylate Porous Polymer Monolithic Column with Measured Phase Ratio
The phase ratio of a chromatographic system is an important measurement that has long been estimated or calculated, but rarely directly measured. This study utilized a nanoflow liquid chromatography instrument to more accurately measure the phase ratio for a lauryl acrylate porous polymer monolith. Direct measurement of the phase ratio, and its dependence on temperature, allows for a better understanding of the thermodynamics of retention of small analytes. This study investigates the retention of an alkyl benzene series, toluene to octylbenzene, via capillary electrochromatography. The phase ratio was determined to be 0.202 at 303 K and 0.213 at 333 K. Using the directly measured phase ratio, entropic contributions to retention can also be obtained. Therefore, the Gibbs free energy calculations from these measurements and methods can give insight to modes of retention. The free energy of retention for toluene is â3.97 kJ/mol at 303 K and â3.78 kJ/mol at 333 K. The trends for enthalpy, entropy, and Gibbs free energy of transfer show that retention is enthalpically driven in this capillary electrochromatography (CEC) porous polymer monolith system
BRS F63 (Camila): A fresh market potato cultivar, with high yield potential and resistance to virus Y
<div><p>ABSTRACT Camila potato, registered and protected as BRS F63, is a cultivar for the fresh market, with oval tubers of attractive appearance, having shallow eyes, yellow and smooth skin, and light yellow flesh. It presents medium specific gravity (dry matter), which allows greater culinary versatility than âAgataâ. Cooked tubers have a firm texture and distinctive flavor, with potential for use even in gourmet kitchen, for preparing salads and other similar dishes. The vegetative growth cycle and dormancy are medium. It presents high productive potential, with high percentage of marketable tubers. It is moderately resistant to greening. Concerning physiological disorders in the tubers, âBRS F63â (Camila) is similar to âAgataâ and âAsterixâ in crops of subtropical ecosystem, but the incidence increases in plantations outside the Winter crop in tropical ecosystem. It is moderately susceptible to Phytophthora infestans and Alternaria spp., which can be managed effectively with fungicides. It has extreme resistance to virus Y (Ry sto ), which reduces the loss of seed quality, allowing more generations of multiplication.</p></div
An essential developmental function for murine phosphoglycolate phosphatase in safeguarding cell proliferation
Mammalian phosphoglycolate phosphatase (PGP) is thought to target phosphoglycolate, a 2-deoxyribose fragment derived from the repair of oxidative DNA lesions. However, the physiological role of this activity and the biological function of the DNA damage product phosphoglycolate is unknown. We now show that knockin replacement of murine Pgp with its phosphatase-inactive Pgp(D34N) mutant is embryonically lethal due to intrauterine growth arrest and developmental delay in midgestation. PGP inactivation attenuated triosephosphate isomerase activity, increased triglyceride levels at the expense of the cellular phosphatidylcholine content, and inhibited cell proliferation. These effects were prevented under hypoxic conditions or by blocking phosphoglycolate release from damaged DNA. Thus, PGP is essential to sustain cell proliferation in the presence of oxygen. Collectively, our findings reveal a previously unknown mechanism coupling a DNA damage repair product to the control of intermediary metabolism and cell proliferation