| AUTHOR |
TITLE |
Jürgen H. Nett,
Bernard L. Trumpower |
Intermediate Length Rieske Iron-Sulfur Protein Is Present and Functionally Active in the Cytochrome bc1 Complex of Saccharomyces cerevisiae
J. Biol. Chem. 1999 274: 9253-9257. |
Experimental Procedures
Cytochrome c Reductase Activity Measurements
Ubiquinol-cytochrome c oxidoreductase activities of mitochondrial membranes and purified bc1 complexes were assayed in 50 mM potassium phosphate, pH 7.0, 250 mM sucrose, 0.2 mM EDTA, 1 mM NaN3, 0.1% (w/v) bovine serum albumin at 23 °C using 80 µM 2,3-dimethoxy-5-methyl-6n-decyl-1,4-benzoquinol as substrate and 50 µM cytochrome c. Reduction of cytochrome c was monitored in an Aminco DW-2a spectrophotometer at 550 versus 539 nm in dual wavelength mode. Data were collected and analyzed using an Online Instrument Systems Inc. computer interface and software. |
Amy S. Hearn,
Chingkuang Tu,
Harry S. Nick,
David N. Silverman |
Characterization of the Product-inhibited Complex in Catalysis by Human Manganese Superoxide DismutaseJ. Biol. Chem. 1999 274: 24457-24460. |
Materials and Methods
Scanning Stopped-flow
Properties of the enzyme in its reaction with product hydrogen peroxide were monitored by observation of the visible absorption spectrum of Mn-SOD and Y34F Mn-SOD using a rapid scanning stopped-flow spectrophotometer (On-Line Instrument Systems, Inc., Bogart, Georgia or Applied Photophysics, Ltd. SX.18MV). |
Jyothi Ghanta,
Chih-Lung Shen,
Laura L. Kiessling,
Regina M. Murphy |
A Strategy for Designing Inhibitors of Beta-Amyloid Toxicity
J. Biol. Chem. 1996 271:29525-29528. |
Experimental Procedures:
Circular Dichroism Spectroscopy
Circular dichroism spectra in the far UV (190-240 nm) were obtained using a modified Cary Model 60 spectropolarimeter (On-line Instrument Systems, Bogart, CA) and analyzed for secondary structure as described (20). |
Skibo, E. B.,
Xing, C. |
Chemistry and DNA Alkylation Reactions of Aziridinyl Quinones: Development of an Efficient Alkylating Agent of the Phosphate Backbone
Biochemistry; 1998; 37(43);15199-15213. |
Methods:
UV-visible spectroscopic/kinetic studies were carried out on a OLIS modified Cary 14 spectrometer. |
Assefa, Z.,
Stanbury, D. |
Oxidation of Coordinated Ammonia to Nitrosyl in the Reaction of Aqueous Chlorine with cis-[Ru(bpy)2(NH3)2]2+
Journal of the American Chemical Society; 1997; 119(3); 521-530. |
Instrumental Methods:
The output from the SU-40 unit was collected by an On-line Instruments (OLIS) 4300 data acquisition system based on a Zenith computer. The rate constants were evaluated by exponential fits with the OLIS subroutines. The final studies were conducted on the OLIS rapid scanning monochromator (RSM 1000) with a dual-beam UV-vis recording and a global fitting subroutine.
For the RU(II) system the spectral profile changes were followed in both the visible and UV regions and the kinetics was analyzed using the global fitting subroutine of the RSM 1000 system. For the Ru(III) reaction the spectral changes were monitored in the UV region (320-440 nm) by use of the RSM 1000 system, and were further analyzed using the Specfit software package. |
Connick, W. B.,
Gray, H. B. |
Photooxidation of Platinum(II) Diimine Dithiolates
Journal of the American Chemical Society; 1997; 119(48); 11620-11627. |
| General Procedures and Instrumentation. UV-vis spectra were recorded using a Cary-14 spectrometer upgraded by OLIS to include computer control. |
Ram, C. G.,
Ram, M. S.,
Yap, G. P. A.,
Liable-Sands,L.,
Rheingold, A. L.,
Marchaj, A.,
Norton, J. R. |
Kinetics and Mechanism of Alkyl Transfer from Organocobalt(III) to Nickel(I): Implications for the Synthesis of Acetyl Coenzyme A by CO Dehydrogenase
Journal of the American Chemical Society; 1997; 119(7); 1648-1655. |
Stopped-Flow Experiments:
The stopped-flow system was configured and used as described elsewhere with the following modifications. An On-Line Instrument Systems RSM 1000 rapid scanning monochromator was used to scan the UV-vis region at 1-ms intervals over an adjustable 300-nm wavelength range. The system was controlled and the spectral and kinetic data were analyzed with OLIS RSM software on a Dell 4100 DM microcomputer. The reagent solutions were prepared and handled under Ar at 25 ± 0.1 °C. [Ni(tmc)]OTf was always present in at least 10-fold excess. For each set of reagent concentrations, data from about six kinetic runs were collected and the observed rate constants averaged. |
Wilson, W. D.,
Tanious, F. A.,
Ding, D.,
Kumar, A.,
Boykin, D. W.,
Colson, P.,
Houssier, C.,
Bailly, C. |
Nucleic Acid Interactions of Unfused Aromatic Cations: Evaluation of Proposed Minor-Groove, Major-Groove, and Intercalation Binding Modes
Journal of the American Chemical Society; 1998; 120(40); 10310-10321. |
Experimental Section:
Kinetics
Kinetics experiments were conducted on an Olis RSM 1000 scanning stopped-flow spectrometer interfaced to a Gateway 2000 PC computer. Data collection and analysis were with the RSM-1000 software. Single exponential fits to the results generally give unsatisfactory residuals and significantly higher root mean square deviations with all the complexes of these compounds with polyd(A-T)2 and polyd(G-C)2. Two exponential fits to the data give satisfactory residuals, and three exponential fits do not significantly improve the residuals or root mean square deviations. |
Tanious, F. A.,
Ding, D.,
Patrick, D. A.,
Tidwell, R. R.,
Wilson, W. D. |
A New Type of DNA Minor-Groove Complex: Carbazole Dication-DNA Interactions
Biochemistry; 1997; 36(49); 15315-15325. |
Materials and Methods:
Kinetics
Kinetics experiments were conducted on an Olis RSM 1000 scanning stopped-flow spectrometer interfaced to Gateway 2000 PC computer. Global analysis is provided with the RSM-1000 software, and single wavelength fitting can be performed at any selected wavelength. |
Pidcock, E.,
Obias, H. V.,
Abe, M.,
Liang, H.-C.,
Karlin, K. D.,
Solomon, E. I. |
Spectroscopic and Theoretical Studies of Oxygenated Dicopper(I) Complexes Containing Hydrocarbon-Linked Bis[2-(2-pyridyl)ethyl]amine Units: Investigation of a Butterfly [Cu2(µn2:H2)(O2)] 2+ Core
Journal of the American Chemical Society; 1999; 121(6);1299-1308. |
Experimental Section:
The absorption spectra of [Cu2(NnPY2)O2][ClO4-]2 (where n = 3-5) were obtained at -80°C in CH2Cl2 by using the HP 8452 diode array spectrophotometer with OLIS diode-array Operating System Version 15.01 program. The spectrophotometer was adapted with a light-proof rectangular box fitted to the sample compartment to allow the insertion of a Kontes KM-611772 variable-temperature vis/UV Dewar cell (including cuvette assembly). Cooling was achieved by inserting a coil of copper tubing into the methanol-filled Dewar through which cold methanol was circulated from an external source (Neslab ULT-95DD Cryocool immersion cooler, with Endocal refrigerated circulating pump). The temperature was monitored with an Omega Model 651 resistance thermometer probe. |
