Nicole M. Nichols

Learn More
The ability to separately purify the naturally split Synechocystis sp. PCC6803 (Ssp) DnaE intein domains has allowed detailed examination of both universal and Ssp DnaE intein-specific steps in the protein splicing pathway. By engineering substitutions at both the +1 and penultimate intein positions, we have further characterized intein reaction kinetics in(More)
Studies were conducted to assess the possible protective action of 16,16-dimethyl prostaglandin E2 (DMPG) against acute aflatoxin B1 (AFB1) induced hepatic injury in the rat. Evaluation of liver damage by histopathologic techniques and clinical chemistry indicated that hepatic necrosis was ameliorated by treatment with DMPG even though binding of(More)
Timoprazole, a substituted benzimidazole, is an antisecretory agent that inhibits gastric acid secretion by interference with (H+-K+)-ATPase. In the studies reported herein, timoprazole given orally was found to be cytoprotective for the stomach when given 30 min prior to a challenge to boiling water, ethanol, or 0.6 N HCl. Timoprazole also prevented(More)
16,16-Dimethyl PGE2 (dmPGE2) has previously been shown to protect the in vivo rat liver against CCl4-induced damage. These studies were undertaken to determine if this protection could be demonstrated in vitro where factors of absorption, secretion, and blood flow are not present. Primary hepatocyte cultures were established by perfusing rat liver with(More)
Use of the naturally split, self-splicing Synechocystis sp. PCC6803 DnaE intein permits separate purification of the N- and C-terminal intein domains. Otherwise spontaneous intein-mediated reactions can therefore be controlled in vitro, allowing detailed study of intein kinetics. Incubation of the Ssp DnaE intein with ZnCl(2) inhibited trans splicing,(More)
Full-length human p53 protein was examined using tryptophan fluorescence and circular dichroism spectroscopy (CD) to monitor unfolding. No significant alteration in tryptophan fluorescence for the tetrameric protein was detectable over a wide range of either urea or guanidine hydrochloride concentrations, in contrast to results with the isolated DNA binding(More)
Full-length p53 protein purified from Escherichia coli in the unmodified, "latent" form was examined by several methods to correlate thermal stability of structure with functional DNA binding. Structure prediction algorithms indicate that the majority of beta-sheet structure occurs in the p53 core DNA binding domain. Circular dichroism spectra demonstrate(More)
DNA binding is crucial to the protective role of the tumor suppressor protein p53, a nuclear phosphoprotein and transcription factor. The mutant human p53 protein S392E is a phosphorylation mimic that has been previously demonstrated to represent an "activated" form of p53 in both in vivo and in vitro assays [Hupp and Lane (1995) J. Biol. Chem. 270, 18165;(More)
This unit describes DNA-dependent, RNA-dependent, and template-independent RNA polymerases. DNA-dependent RNA polymerases include the related bacteriophage T7, T3, and SP6 polymerases, the most commonly used RNA polymerases for in vitro transcription reactions. Reaction conditions to produce preparative quantities of transcribed RNA and labeled RNA probes(More)
This unit describes a simple and efficient DNA engineering method that combines nucleotide sequence alteration, multiple PCR fragment assembly, and directional cloning. PCR primers contain a single deoxyuracil residue (dU), and can be designed to accommodate nucleotide substitutions, insertions, and/or deletions. The primers are then used to amplify DNA in(More)