A5111661828- Hemoglobin structure and function
- Photosynthetic Processes and Mechanisms
- Enzyme Structure and Function
- Photoreceptor and optogenetics research
- Mass Spectrometry Techniques and Applications
- Protein Structure and Dynamics
- Lipid Membrane Structure and Behavior
- Electrochemical Analysis and Applications
- Enzyme-mediated dye degradation
- Electrochemical sensors and biosensors
- Electron Spin Resonance Studies
- Spectroscopy and Quantum Chemical Studies
- Protein Interaction Studies and Fluorescence Analysis
- Heme Oxygenase-1 and Carbon Monoxide
- Biosensors and Analytical Detection
- Trace Elements in Health
- Metal-Catalyzed Oxygenation Mechanisms
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced X-ray Imaging Techniques
- Neonatal Health and Biochemistry
- Erythrocyte Function and Pathophysiology
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Crystallography and Radiation Phenomena
- Advanced MRI Techniques and Applications
- Advanced Optical Sensing Technologies
Purdue University West Lafayette
2025
University of Iowa
2021-2025
Sanofi (United States)
2023
University of Arizona
2009
Utah State University
1993-2005
University of Nebraska–Lincoln
1986-1999
University of Pennsylvania
1980-1997
Himeji University
1996
Bristol-Myers Squibb (United States)
1994
Hirosaki University
1993
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructural studies of the hemocyanin active site. 1. Extended x-ray absorption fine structure (EXAFS) analysisJ. M. Brown, L. Powers, B. Kincaid, J. A. Larrabee, and T. G. SpiroCite this: Am. Chem. Soc. 1980, 102, 12, 4210–4216Publication Date (Print):June 1, 1980Publication History Published online1 May 2002Published inissue 1 June 1980https://pubs.acs.org/doi/10.1021/ja00532a037https://doi.org/10.1021/ja00532a037research-articleACS...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHead-group conformation in phospholipids: a 31P nuclear magnetic resonance study of oriented monodomain dipalmitoylphosphatidylcholine bilayersR. G. Griffin, L. Powers, and P. S. PershanCite this: Biochemistry 1978, 17, 14, 2718–2722Publication Date (Print):July 11, 1978Publication History Published online1 May 2002Published inissue 11 July 1978https://pubs.acs.org/doi/10.1021/bi00607a004https://doi.org/10.1021/bi00607a004research-articleACS...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEXAFS studies of binuclear copper site oxy-, deoxy-, and metaquo-, metfluoro-, metazidohemocyanin from arthropods molluscsG. L. Woolery, Powers, M. Winkler, E. I. Solomon, T. G. SpiroCite this: J. Am. Chem. Soc. 1984, 106, 1, 86–92Publication Date (Print):January 1984Publication History Published online1 May 2002Published inissue 1 January 1984https://pubs.acs.org/doi/10.1021/ja00313a019https://doi.org/10.1021/ja00313a019research-articleACS...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure and kinetics of the photoproduct carbonylmyoglobin at low temperatures; an x-ray absorption studyB. Chance, R. Fischetti, L. PowersCite this: Biochemistry 1983, 22, 16, 3820–3829Publication Date (Print):August 2, 1983Publication History Published online1 May 2002Published inissue 2 August 1983https://pubs.acs.org/doi/10.1021/bi00285a017https://doi.org/10.1021/bi00285a017research-articleACS PublicationsRequest reuse permissionsArticle...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTX-ray absorption studies of myoglobin peroxide reveal functional differences between globins and heme enzymesM. Chance, L. Powers, C. Kumar, B. ChanceCite this: Biochemistry 1986, 25, 6, 1259–1265Publication Date (Print):March 1, 1986Publication History Published online1 May 2002Published inissue 1 March 1986https://pubs.acs.org/doi/10.1021/bi00354a010https://doi.org/10.1021/bi00354a010research-articleACS PublicationsRequest reuse...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCytochrome c peroxidase compound ES is identical with horseradish I in iron-ligand distancesM. Chance, L. Powers, T. Poulos, and B. ChanceCite this: Biochemistry 1986, 25, 6, 1266–1270Publication Date (Print):March 1, 1986Publication History Published online1 May 2002Published inissue 1 March 1986https://pubs.acs.org/doi/10.1021/bi00354a011https://doi.org/10.1021/bi00354a011research-articleACS PublicationsRequest reuse permissionsArticle...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetic, structural, and spectroscopic indentification of geminate states myoglobin: a ligand binding site on the reaction pathwayL. Powers, B. Chance, M. Campbell, J. Friedman, S. Khalid, C. Kumar, A. Naqui, K. Reddy, Y. ZhouCite this: Biochemistry 1987, 26, 15, 4785–4796Publication Date (Print):July 28, 1987Publication History Published online1 May 2002Published inissue 28 July...
Previous studies [Chance, B., Fischetti, & Powers, L. (1983) Biochemistry 22, 3820-3829] of the local structure changes around iron in carboxymyoglobin on photolysis at 4 K revealed that iron-carbon distance increased approximately 0.05 A but was accompanied by a lengthening iron-pyrrole nitrogen bonds heme (approximately 0.03 A) not as large found deoxy form. Further analysis these data together with comparison to model compounds indicates Fe-C-O bond angle is bent (127 +/- degrees), having...
At neutral pH, compound I of Arthromyces ramosus peroxidase (ARP) was stable and reduced to ferric ARP without apparent formation II upon titration with ascorbate or hydroquinone. In the experiments, seen as an intermediate only at alkaline pH. However, measuring a difference spectrum in Soret region by stopped-flow method, we found that formed during catalytic oxidation even Using EPR spectrometer microflow system, measured steady-state concentration benzosemiquinone ARP-catalyzed The...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure and reactivity of multiple forms cytochrome oxidase as evaluated by x-ray absorption spectroscopy kinetics cyanide bindingAli Naqui, Chellappa Kumar, Yuan Chin Ching, L. Powers, Britton ChanceCite this: Biochemistry 1984, 23, 25, 6222–6227Publication Date (Print):December 1, 1984Publication History Published online1 May 2002Published inissue 1 December...
A technique for the preparation of large monodomain phospholipid bilayer arrays is described. Evidence nature samples, obtained from optical birefringence, light scattering, and x-ray diffraction experiments, presented.
X-ray absorption spectroscopy is ideally suited for the investigation of electronic structure and local environment (approximately 5 A) specific atoms in biomolecules. While edge region provides information about valence state absorbing atom, chemical identity neighboring atoms, coordination geometry, extended x-ray fine contains number average distance their relative disorder. The development sensitive detection methods has allowed studies using near physiological concentrations (as low as...
Avalanche photodiode detectors (APDs) at X-ray synchrotrons are typically limited to recording most one photon per synchrotron pulse. Digitizing the APD amplifier outputs enables signal processing accurately measure a mean count rate of least four photons pulse based on initial measurements. Higher rates readily achievable. This method allows APDs be utilized for time-resolved measurements much higher intensities than before.
Beam splitters are utilized in a variety of advanced x-ray instruments and essential for extending quantum optics techniques to x rays. A new fabrication method has produced thinned Bragg diffracting silicon devices with variable reflectivity transmission coefficients negligible absorption losses. Diffraction measurements confirm that continues exhibit perfect crystal diffraction even thicknesses below two microns. Devices machined from standard wafers, the regions contained within robust...