Sara K Wright

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The crystal structure of F65A/Y131C murine alpha-carbonic anhydrase V (CAV), covalently modified at cysteine residues with 4-chloromethylimidazole, is reported at 1.88 A resolution. This modification introduces a methylimidazole (MI) group at residue C131 in the active site with important consequences. F65A/Y131C-MI CAV exhibits an up to 3-fold enhancement(More)
Several methods for the quantitation of cysteines in proteins have been evaluated and compared. Titration of protein sulfhydryl groups with 5,5'-dithiobis(2-nitrobenzoate) (DTNB) under carefully controlled conditions has extended the detection limits of this method with high accuracy and reproducibility. Results are reported for a variety of enzymes(More)
The important biosynthetic intermediate chorismate reacts thermally by two competitive pathways, one leading to 4-hydroxybenzoate via elimination of the enolpyruvyl side chain, and the other to prephenate by a facile Claisen rearrangement. Measurements with isotopically labeled chorismate derivatives indicate that both are concerted sigmatropic processes,(More)
The rate-limiting step in the catalysis of the hydration of CO2 by carbonic anhydrase involves transfer of protons between zinc-bound water and solution. This proton transfer can be enhanced by proton shuttle residues within the active-site cavity of the enzyme. We have used chemical modulation to provide novel internal proton transfer groups that enhance(More)
Malate dehydrogenase specifically oxidizes malate to oxaloacetate. The specificity arises from three arginines in the active site pocket that coordinate the carboxyl groups of the substrate and stabilize the newly forming hydroxyl/keto group during catalysis. Here, the role of Arg-153 in distinguishing substrate specificity is examined by the mutant R153C.(More)
The levels of 20 elements (Al, Ca, Cd, Cl, Co, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, Sb, Se, V, and Zn) are reported for kidney, liver, muscle, spleen, and brain tissues taken from two groups of six steers per group in a feeding study conducted at Colorado State University. The control group was fed a normal feedlot cattle ration and the test group was(More)
We performed a fragment screen on the dengue virus serotype 3 RNA-dependent RNA polymerase using x-ray crystallography. A screen of 1,400 fragments in pools of eight identified a single hit that bound in a novel pocket in the protein. This pocket is located in the polymerase palm subdomain and conserved across the four serotypes of dengue virus. The(More)
Dengue virus (DENV) is the most significant mosquito-borne viral pathogen in the world and is the cause of dengue fever. The DENV RNA-dependent RNA polymerase (RdRp) is conserved among the four viral serotypes and is an attractive target for antiviral drug development. During initiation of viral RNA synthesis, the polymerase switches from a "closed" to(More)
Malate dehydrogenase (MDH) from Escherichia coli is highly specific for its keto acid substrate. The placement of the active site-binding groups in MDH effectively discriminates against both the shorter and the longer keto dicarboxylic acids that could potentially serve as alternative substrates. A notable exception to this specificity is the alternative(More)
The determination of accurate binding affinities is critical in drug discovery and development. Several techniques are available for characterizing the binding of small molecules to soluble proteins. The situation is different for integral membrane proteins. Isothermal chemical denaturation has been shown to be a valuable biophysical method to determine, in(More)