Structure and Dynamics of CO−Iron(II) Protoporphyrin IX in Dimethyl Sulfoxide

Larsen, Randy W.; Murphy, James R.; Findsen, E. W.

doi:10.1021/ic950998c

Cited by 16 publications

(18 citation statements)

References 25 publications

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“…Exposure of the heme–Fe II solution to CO immediately provides CO–heme–Fe II ( λ max 411, 535, and 565 nm), in accordance with previous data 12–15. The stability of model CO–heme–Fe II systems has been noted; comparison with CO–Hb–Fe II shows a several thousandfold greater stability 16.…”

Section: Resultssupporting

confidence: 89%

Biofuel Cells for Biomedical Applications: Colonizing the Animal Kingdom

et al. 2013

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Interdisciplinary research has combined the efforts of many scientists and engineers to gain an understanding of biotic and abiotic electrochemical processes, materials properties, biomedical, and engineering approaches for the development of alternative power-generating and/or energy-harvesting devices, aiming to solve health-related issues and to improve the quality of human life. This review intends to recapitulate the principles of biofuel cell development and the progress over the years, thanks to the contribution of cross-disciplinary researchers that have combined knowledge and innovative ideas to the field. The emergence of biofuel cells, as a response to the demand of electrical power devices that can operate under physiological conditions, are reviewed. Implantable biofuel cells operating inside living organisms have been envisioned for over fifty years, but few reports of implanted devices have existed up until very recently. The very first report of an implanted biofuel cell (implanted in a grape) was published only in 2003 by Adam Heller and his coworkers. This work was a result of earlier scientific efforts of this group to "wire" enzymes to the electrode surface. The last couple of years have, however, seen a multitude of biofuel cells being implanted and operating in different living organisms, including mammals. Herein, the evolution of the biofuel concept, the understanding and employment of catalyst and biocatalyst processes to mimic biological processes, are explored. These potentially green technology biodevices are designed to be applied for biomedical applications to power nano- and microelectronic devices, drug delivery systems, biosensors, and many more.

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Section: Resultssupporting

confidence: 89%

Biofuel Cells for Biomedical Applications: Colonizing the Animal Kingdom

et al. 2013

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“…This tendency is even more obvious for the mutant F87A that has shown a large variation in the size of the mouth entrance with respect to the crystallographic conformations. The tendency of a DMSO molecule to bind the heme iron has been shown experimentally in different heme–proteins and in isolated porphyrin models 39–43. This experimental evidence shows that Fe(III) can interact with the sulphoxide oxygen and sulphur atom, forming stable complexes.…”

Section: Discussionmentioning

confidence: 84%

Resolution and reproducibility of BOLD and perfusion functional MRI at 3.0 Tesla

Gelderen

Zwart

Cohen

et al. 2005

Magnetic Resonance in Med

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Visual and somatosensory activation studies were performed on normal subjects to compare the spatial discrimination and reproducibility between functional MRI (fMRI) methods based on blood oxygen level-dependent (BOLD) and perfusion contrast. To allow simultaneous measurement of BOLD and perfusion contrast, a dedicated MRI acquisition technique was developed. Repeated experiments of sensory stimulation of single digits of the right hand showed an average variability of activation amplitude of 25% for BOLD data, and a significantly lower variability of 21% for perfusion data. No significant difference in the variability of the locus of activity was observed between the BOLD and perfusion data. In somatotopy experiments, digits II and V were subjected to passive sensory stimulation. Both the BOLD and perfusion data showed substantial overlap in the activation patterns from the two digits. In a retinotopy study, two stimuli were alternated to excite different patches of V1. Again there was substantial overlap between the activation patterns from both stimuli, although the perfusion performed somewhat better than the BOLD method. Particularly for the visual studies, the overlap in activation patterns was more than expected based on the fine-scale retinotopic mapping of cortical activity, suggesting that both BOLD and perfusion contrast mechanisms contribute substantially to the point-spread function ( Changes in tissue perfusion with brain activation can be measured with MRI methods sensitized to perfusion contrast (1) or blood oxygenation level-dependent (BOLD) contrast (2). Since perfusion changes are the source of and potentially precede blood oxygenation changes, it can be argued that perfusion MRI is a more direct method for detecting brain activity. This can lead to distinct differences between perfusion and BOLD measures of activity, with potentially important implications for functional activation studies.One potential difference between perfusion and BOLD functional MRI (fMRI) is in the accuracy of localization (3). Perfusion fMRI is thought to be primarily sensitized to the arterial side of the capillary bed, with a potential contribution from the arterioles and larger arteries. BOLD fMRI, on the other hand, has a bias toward the venous side of the capillary bed and can include venules and the larger veins, as well as their surrounding tissue. This sensitivity to venous or arterial effects can result in localization errors of a few to several millimeters depending on the contribution of signals from outside the capillary bed (i.e., the macrovascular contribution).The difference in contrast mechanisms between BOLD and perfusion MRI can also lead to differences in the reproducibility of the localization and the amplitude of the activation. Since BOLD fMRI relies on an imbalance between changes in vascular oxygen extraction and perfusion, one could argue that perfusion contrast, which does not rely on this imbalance, might be a more robust and reproducible measure.Despite the potential problems related to loc...

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“…The tendency of a DMSO molecule to bind the heme iron has been shown experimentally in different heme-proteins and in isolated porphyrin models. [39][40][41][42][43] This experimental evidence shows that Fe(III) can interact with the sulphoxide oxygen and sulphur atom, forming stable complexes. The result of our simulation shows that DMSO tends to interact with the iron.…”

Section: Discussionmentioning

confidence: 90%

Toward understanding the inactivation mechanism of monooxygenase P450 BM‐3 by organic cosolvents: A molecular dynamics simulation study

et al. 2006

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Cytochrome P450 BM-3 from Bacillus megaterium is an extensively studied enzyme for industrial applications. A major focus of current protein engineering research is directed to improving the catalytic performance of P450 BM-3 toward nonnatural substrates of industrial importance in the presence of organic solvents or cosolvents. For the latter reason, it is important to study the effect of organic cosolvent molecules on the structure and dynamics of the enzyme, in particular, the effect of cosolvent molecules on the active site's structure and dynamics. In this paper, we have studied, using molecular dynamics (MD) simulations, the F87A mutant of P450 BM-3 in the presence of DMSO as cosolvent, to understand the role of the F87A substitution for its catalytic activity. This mutant exhibits an altered regioselectivity and substrate specificity compared with wild-type; however, it has lower tolerance toward DMSO. The simulation results offer an explanation for the DMSO sensitivity of the F87A mutant. Our simulation results show that the F87 side chain prevents the disturbance of the water molecule bound to the heme iron by DMSO molecules. The absence of the phenyl ring in F87A mutant promotes interactions of the DMSO molecule with the heme iron resulting in water displacement by DMSO at the catalytic heme center.

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Structure and Dynamics of CO−Iron(II) Protoporphyrin IX in Dimethyl Sulfoxide

Cited by 16 publications

References 25 publications

Biofuel Cells for Biomedical Applications: Colonizing the Animal Kingdom

Biofuel Cells for Biomedical Applications: Colonizing the Animal Kingdom

Resolution and reproducibility of BOLD and perfusion functional MRI at 3.0 Tesla

Toward understanding the inactivation mechanism of monooxygenase P450 BM‐3 by organic cosolvents: A molecular dynamics simulation study

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