Compound I Formation and Reactivity in Dimeric Chlorite Dismutase: Impact of pH and the Dynamics of the Catalytic Arginine

<ul> <li><strong>Data type</strong>: spectroscopic measurements (UV-visible, ECD, EPR), enzyme activity measurements, mass spectrometry, spectroelectrochemistry and data analysis.</li> <li>Files are in<strong> .DTA, .DSC, .xlsx, .m, .mat, .BSW, .csv, .txt, .dsx, .pdf, .uds </strong>formats</li> <li>Information on <strong>origin of the data</strong>: <ul> <li>EPR spectroscopic measurements in <strong>DTA </strong>and<strong> DSC</strong> formats</li> <li>EPR spectroscopic simulation and analyses in <strong>m </strong>and<strong> mat</strong> format</li> <li>Analysis of Rapid Freeze-Quench calibration curve is in <strong>xlsx</strong> format</li> <li>UV-vis spectroscopic measurements in <strong>csv, xlsx, txt, uds and dsx</strong> format</li> <li>ECD measurements in <strong>csv, xlsx and dsx</strong> format</li> <li>Enzyme activity data in <strong>csv and xlsx</strong> format</li> <li>Mass spectrometry data in <strong>pdf and xlsx</strong> format</li> <li>Spectroelectrochemistry data in <strong>BSW</strong> and <strong>xlsx</strong> format</li> </ul> </li> <li>The data are <strong>generated</strong> by: <ul> <li>UV&minus;vis spectra were recorded using a Cary 60 UV&ndash;vis spectrophotometer (Agilent) and a U-3900 spectrophotometer (Hitachi, Mannheim, Germany).</li> <li>Electronic circular dichroism spectroscopy was performed using Chirascan (Applied Photophysics, Leatherhead, UK).</li> <li>Rapid Freeze-Quench of EPR sample was performed with the use of a device from BioLogic (Grenoble, France), consisting of an SFM-2000 stopped-flow unit and an MPS-70 controller unit, combined with a freeze-quench sample collector adapted for EPR tubes. The ejected volumes and flow rate were controlled by the BioLogic BIOKINE software, v. 4.72.</li> <li>X-Band CW-EPR experiments were performed on X-band ELEXSYS E580 spectrometer (Bruker BioSpin GmbH) operating at a microwave frequency of &sim;9.4 GHz and equipped with a standard TE102 cavity and a liquid He cryostat (Oxford Inc.)</li> <li>Enzyme activity was measured polarographically following the release of O₂ by using a Clark-type oxygen electrode (Oxygraph Plus; Hansatech Instruments, Norfolk, UK).</li> <li>Stopped-flow spectroscopy measurements were performed with a SX-18MV or Pi-star from Applied Photophysics using either a diode array detector or a monochromator and photomultiplier detector.</li> <li>Mass spectrometry analysis was performed with an ion-trap mass spectrometer (amaZon speed ETD, Bruker) equipped with the standard ESI source in positive ion, DDA mode (i.e., switching to MSMS mode for eluting peaks).</li> <li>All spectroelectrochemistry experiments were conducted in a homemade OTTLE (optical transparent thin-layer spectroelectrochemical) cell. In detail, the three-electrode configuration consisted of a gold minigrid working electrode (Buckbee-Mears, Chicago, IL), a homemade Ag/AgCl/KCl_sat microreference electrode separated from the working solution by a Vycor set, and a platinum wire as the counter electrode. UV&minus;vis spectra were recorded using a Varian Cary C50 spectrophotometer.</li> </ul> </li> </ul> <p>&nbsp;</p> <p>&nbsp;</p> <ul> <li>If the dataset includes multiple files that relate to each other: <ul> <li>Files in <strong>PARACAT_WP3_20230302_01_EPR </strong>folder includes EPR spectroscopic measurements and computer simulations/analyses, original data are in <strong>DTA/DSC</strong> formats; files in <strong>m</strong> format were used to process the data.</li> <li>Files in <strong>PARACAT_WP3_20230302_02_UVVIS </strong>folder includes sequential and non-sequential stopped flow data, measured with detection by photodiode array or monochromator (time traces): original data is in <strong>dsx and csv </strong>format<strong>, xlsx </strong>format contains processed data; conventional photometric data is originally in <strong>txt and uds </strong>format, <strong>xlsx </strong>format contains processed data</li> <li>Files in <strong>PARACAT_WP3_20230302_03_ECD</strong> folder contain ECD spectra: original data is in <strong>dsx and csv </strong>format<strong>, xlsx </strong>format contains processed data</li> <li>Files in <strong>PARACAT_WP3_20230302_04_Enzyme activity </strong>folder contain polarographically detected changes in dioxygen concentration, due to enzyme activity: original data is in <strong>csv </strong>format<strong>, xlsx </strong>format contains processed data</li> <li>Files in <strong>PARACAT_WP3_20230302_05_MassSpec </strong>folder contain mass spectrometry data for the MNP assay: original data is in <strong>pdf </strong>format<strong>, xlsx </strong>format contains processed data</li> <li>Files in <strong>PARACAT_WP3_20230302_06_Spectroelectrochemistry </strong>folder includes spectroelectrochemistry measurements and computer analyses, original data are in <strong>BSW</strong> formats; files in <strong>xlsx</strong> format were used to process the data.</li> </ul> </li> </ul> <p>&nbsp;</p> <p>NB. See the &ldquo;READ ME&rdquo; text file in each subfolder for more detailed information on files organization.</p> <p>&nbsp;</p> <ul> <li>Information on: <ul> <li><strong>Abbreviations:</strong> <ul> <li>, chlorite dismutase; <strong><em>C</em>Cld</strong>, chlorite dismutase from Cyanothece sp. PCC7425; <strong>CcP</strong>, cytochrome c peroxidase;<strong> DaCld</strong>, chlorite dismutase from <em>Dechloromonas aromatica</em>; <strong>E&deg;&prime;</strong>, standard reduction potential; <strong>ECD</strong>, electronic circular dichroism; <strong>EPR</strong>, electron paramagnetic resonance; <strong>HRP</strong>, horseradish peroxidase; <strong>LPO</strong>, lactoperoxidase; <strong>MNP</strong>, 2-methyl-2-nitrosopropane; <strong>MPO</strong>, myeloperoxidase; <strong>PAA</strong>, peracetic acid; <strong>RFQ</strong>, rapid freeze-quench.</li> </ul> </li> </ul> </li> </ul> <p>&nbsp;</p> <ul> <li><strong>Units of measurement</strong>: <ul> <li>Concentration: <strong>mM</strong> (millimolar), <strong>&micro;M</strong> (micromolar), <strong>nM</strong> (nanomolar), <strong>mg/mL</strong> (milligrams per milliliter)</li> <li>Molecular mass: <strong>Da</strong> (Dalton)</li> <li>Absorptivity: <strong>M^-1</strong> <strong>cm^-1</strong></li> <li>Volume: <strong>mL</strong> (milliliters), <strong>&micro;L </strong>(microliters), <strong>nL</strong> (nanoliters)</li> <li>Wavelength:<strong> nm</strong> (nanometers)</li> <li>Temperature:<strong> &deg;C</strong> (Celsius degrees), <strong>K</strong> (Kelvin degrees)</li> <li>Time:<strong> ms</strong> (milliseconds), <strong>s</strong> (seconds), <strong>min</strong> (minutes), <strong>h</strong> (hours),</li> <li>Ellipticity: millidegrees</li> <li>Frequency: <strong>GHz</strong> (gigahertz), <strong>kHz</strong> (kilohertz)</li> <li>Power: <strong>mW</strong> (milliwatt)</li> <li>Magnetic field: <strong>mT</strong> (milliTesla)</li> <li>Reduction potential: <strong>mV </strong>(milliVolts)</li> </ul> </li> </ul>