D W Ledman

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In order to help determine the extent to which side chain interactions within the staphylococcal nuclease beta-barrel affect its global stability, a full set of point mutants was generated for residue 27. Intrinsic tryptophan fluorescence was monitored during solvent denaturation with guanidine hydrochloride (GuHCl) and was used to calculate DeltaGH2O(More)
Non-native states of proteins populated at extremes of pH, or by mutation or truncation of the protein sequence, are thought to be equilibrium models for kinetic intermediates on the folding pathway. While the global physical properties of these molecules have been well characterized, analysis of their structure by NMR spectroscopy has proven difficult.(More)
The protein subunit of Escherichia coli ribonuclease P (which has a cysteine residue at position 113) and its single cysteine-substituted mutant derivatives (S16C/C113S, K54C/C113S and K66C/C113S) have been modified using a sulfhydryl-specific iron complex of EDTA-2- aminoethyl 2-pyridyl disulfide (EPD-Fe). This reaction converts C5 protein, or its single(More)
Six single cysteine variants of staphylococcal nuclease were reacted with the iron complex of (EDTA-2-aminoethyl) 2-pyridyl disulfide (EPD-Fe) [Ermácora, M. R., Delfino, J. M., Cuenoud, B., Schepartz, A., & Fox, R. O. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 6383-6387] and used to assess the ability of this cleavage reagent to faithfully report on the(More)
Tissue-specific isozymes of pyruvate kinase are particularly attractive systems to elucidate the molecular mechanism(s) of conferring allostery. The muscle- and kidney-type isozymes are coded by the same gene. As a consequence of alternative message RNA splicing, the two primary sequences differ by a small number of residues. However, they exhibit very(More)
A new enzyme immunoassay (EIA) was used to investigate immunoglobulin M (IgM) and IgG responses to various coccidioidal antigen preparations. Direct binding and inhibition assays both revealed that the IgG responses of many serum specimens were directed largely to the tube precipitin (TP) antigen even when the microwells were coated with a combination of(More)
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