| AUTHOR |
TITLE |
Saurabh Menon,
Stephen W. Ragsdale |
The Role of an Iron-Sulfur Cluster in an Enzymatic Methylation Reaction. METHYLATION OF CO DEHYDROGENASE/ACETYL-CoA SYNTHASE BY THE METHYLATED CORRINOID IRON-SULFUR PROTEIN
J. Biol. Chem. 1999 274: 11513-11518 |
Experimental Procedures:
Enzyme AssaysUV-visible spectra were obtained on an OLIS-modified Cary 14 spectrometer. |
Ilia V. Baskakov,
Raj Kumar,
Ganesan Srinivasan,
Yan-shan Ji,
D. Wayne Bolen,
E. Brad Thompson |
Trimethylamine N-Oxide-induced Cooperative Folding of an Intrinsically Unfolded Transcription-activating Fragment of Human Glucocorticoid Receptor
J. Biol. Chem. 1999 274: 10693-10696. |
Experimental Procedures:
CD spectra were recorded using a Olis RSM CD Spectrometer at variable scan rate (always slower than 60 nm/min) in 0.1-cm cuvettes thermostatted at 22 °C in 10 mM Tris, 10 mM NaCl buffer, pH 7.9. The bandwidth was 1 nm with data spacing 0.5 nm, and each spectrum shown is the result of 10-20 spectra accumulated, averaged and smoothed. All spectra were corrected for the contributions of the respective buffers. |
Anna L. Shen,
Daniel S. Sem,
Charles B. Kasper |
Mechanistic Studies on the Reductive Half-reaction of NADPH-Cytochrome P450 Oxidoreductase
J. Biol. Chem. 1999 274: 5391-5398. |
Experimental Procedures:
Aerobic stopped-flow studies were carried out on an Olis RSM 100 rapid scanning spectrophotometer. |
Min Xia,
Robert Dempski,
Russ Hille |
The Reductive Half-reaction of Xanthine Oxidase. REACTION WITH ALDEHYDE SUBSTRATES AND IDENTIFICATION OF THE CATALYTICALLY LABILE OXYGEN
J. Biol. Chem. 1999 274: 3323-3330. |
Materials and Methods
Steady-state kinetic experiments were performed under O[(2)]-saturated conditions at 25 șC, using a Kinetic Instruments stopped-flow spectrometer interfaced to a PC-486 personal computer using software from On-Line Instrument Systems, Inc. (OLIS). |
Donald F. Becker,
Ubolsree Leartsakulpanich,
Kristene K. Surerus,
James G. Ferry,
Stephen W. Ragsdale |
Electrochemical and Spectroscopic Properties of the Iron-Sulfur Flavoprotein from Methanosarcina thermophila
J. Biol. Chem. 1998 273: 26462-26469. |
| The visible spectra in each experiment were obtained and stored on an Olis -14 interfaced Cary spectrophotometer. |
Takeshi Uchida,
Haruto Ishikawa,
Satoshi Takahashi,
Koichiro Ishimori,
Isao Morishima,
Kei Ohkubo,
Hiroshi Nakajima,
Shigetoshi Aono |
Heme Environmental Structure of CooA Is Modulated by the Target DNA Binding. EVIDENCE FROM RESONANCE RAMAN SPECTROSCOPY AND CO REBINDING KINETICS
J. Biol. Chem. 1998 273: 19988-19992. |
| The time courses were monitored at 566 nm with a spectrophotometer (Perkin-Elmer, Lambda19) or a rapid scanning monochrometer (Olis, RSM-1000). The sample solutions used for the kinetic measurements typically contained 20 µM CooA in 50 mM Tris/HCl buffer at pH 8.0, 20 °C. |
Qing-Yu He,
Anne B. Mason,
Robert C. Woodworth,
Beatrice M. Tam,
Ross T. A. MacGillivray,
John K. Grady,
N. Dennis Chasteen |
Mutations at Nonliganding Residues Tyr-85 and Glu-83 in the N-Lobe of Human Serum Transferrin. FUNCTIONAL SECOND SHELL EFFECTS
J. Biol. Chem. 1998 273: 17018-17024. |
Experimental Procedures
Electronic Spectra
UV-visible spectra were recorded on a Cary 219 spectrophotometer under the control of the computer program Olis-219s (On-line Instrument Systems, Inc., Bogart, GA). The appropriate buffer (50 mM HEPES, pH 7.4) served as the reference for full-range spectra from 236 to 650 nm. Difference spectra were generated by storing the spectrum of the apo-protein as the base line and subtracting it from the sample spectra. Anion exchange experiments between NTA and carbonate were performed as reported previously. |
Robert J. Baugh,
George J. Broze, Jr.,
Sriram Krishnaswamy |
Regulation of Extrinsic Pathway Factor Xa Formation by Tissue Factor Pathway Inhibitor
J. Biol. Chem. 1998 273: 4378-4386. |
Experimental Procedures
Measurement of the Overall Dissociation Constant (Ki*) for the Inhibition of VIIa·TF by TFPI Alone or by the Xa·TFPI Binary Complex
VIIa·TF activity was measured by the hydrolysis of the fluorescent substrate Z-VVR-AMC. Fluorescence measurements were performed using an SLM 8000C fluorescence spectrophotometer with adapted hardware and software (OLIS, Bogart, GA) as described (41). |
David M. LeMaster,
Penelope A. Springer,
Clifford J. Unkefer |
The Role of the Buried Aspartate of Escherichia coli Thioredoxin in the Activation of the Mixed Disulfide Intermediate
J. Biol. Chem. 1997 272: 29998-30001. |
Experimental Procedures
Fluorescence Stopped Flow Experiments
Fluorescence stopped flow experiments utilized an OLIS RSM spectrophotometer (On Line Instrument Systems, Inc.). The average of at least six mixing experiments were determined for each set of reagent conditions. The pH value of the mixing effluent are reported in all cases. For fluorescence experiments 40 ”M oxidized protein in 0.2 M HEPES buffer was mixed 1:1 with dithiothreitol in 0.5 mM EDTA, disodium salt. Constant ionic strength for the HEPES buffer solution with a [Na+] of 0.2 M was achieved by varying the proportion of 2 M NaOH and 2 M NaCl added to a solution of HEPES in free acid form. The dithiothreitol concentrations used ranged from 5 to 320 mM depending on the pH of the protein solution. An excitation wavelength of 285 nm and emission signals above 325 nm were used. |
L. Chastine Bell,
F. Peter Guengerich |
Oxidation Kinetics of Ethanol by Human Cytochrome P450 2E1. RATE-LIMITING PRODUCT RELEASE ACCOUNTS FOR EFFECTS OF ISOTOPIC HYDROGEN SUBSTITUTION AND CYTOCHROME b5 ON STEADY-STATE KINETICS
J. Biol. Chem. 1997 272: 29643-29651. |
Experimental Procedures
UV-visible spectra were recorded using a modified Cary 14/OLIS spectrophotometer (On-Line Instrument Systems, Bogart, GA). Rates of NADPH oxidation were calculated  340 = 6.22 mM-1 cm-1 for NADPH. |
