Browsing by Author "Pinakoulaki, Eftychia"
Now showing items 21-40 of 43
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Probing the environment of CuB in heme-copper oxidases
Daskalakis, Vangelis; Pinakoulaki, Eftychia; Stavrakis, Stavros; Varotsis, Constantinos (2007)Time-resolved step-scan FTIR (TRS2-FTIR) and density functional theory have been applied to probe the structural dynamics of CuB in heme-copper oxidases at room temperature. The TRS2-FTIR data of cbb3 from Pseudomonas ...
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Probing the ligand recognition and discrimination environment of the globin-coupled oxygen sensor protein YddV by FTIR and time-resolved step-scan FTIR spectroscopy
Pavlou, A.; Martínková, M.; Shimizu, T.; Kitanishi, K.; Stranava, M.; Loullis, Andreas; Pinakoulaki, Eftychia (2015)YddV is a newly discovered signal transducer heme protein that recognizes O2 and CO. Structural differences in the ligand-bound heme complex in YddV reflect variations in catalytic regulation by O2 and CO. Time-resolved ...
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Probing the ligand recognition and discrimination environment of the globin-coupled oxygen sensor protein YddV by FTIR and time-resolved step-scan FTIR spectroscopy1
Pavlou, Andrea; Martínková, Markéta; Shimizu, Toru; Kitanishi, Kenichi; Stranava, Martin; Loullis, Andreas; Pinakoulaki, Eftychia (2015)
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Probing the nitrite and nitric oxide reductase activity of cbb3 oxidase: Resonance Raman detection of a six-coordinate ferrous heme-nitrosyl species in the binuclear b3/CuB center
Loullis, Andreas; Pinakoulaki, Eftychia (2015)In this work we report the first spectroscopic evidence demonstrating that cbb3 oxidase catalyzes the reduction of nitrite to nitrous oxide under reducing anaerobic conditions. The reaction proceeds through the formation ...
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Probing the nitrite and nitric oxide reductase activity of cbb3 oxidase: resonance Raman detection of a six-coordinate ferrous heme–nitrosyl species in the binuclear b3/CuB center1
Loullis, Andreas; Pinakoulaki, Eftychia (2015)
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Protein Dynamics of the Sensor Protein HemAT as Probed by Time-Resolved Step-Scan FTIR Spectroscopy
Pavlou, Andrea; Yoshimura, Hideaki; Aono, Shigetoshi; Pinakoulaki, Eftychia (2018)The heme-based aerotactic transducer (HemAT) is an oxygen-sensor protein consisting of a sensor and a signaling domain in the N- and C-terminal regions, respectively. Time-resolved step-scan FTIR spectroscopy was employed ...
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The protein effect in the structure of two ferryl-oxo intermediates at the same oxidation level in the heme copper binuclear center of cytochrome c oxidase
Pinakoulaki, Eftychia; Daskalakis, Vangelis; Ohta, T.; Richter, O. -M H.; Budiman, K.; Kitagawa, T.; Ludwig, B.; Varotsis, Constantinos (2013)Identification of the intermediates and determination of their structures in the reduction of dioxygen to water by cytochrome c oxidase (CcO) are particularly important to understanding both O2 activation and proton pumping ...
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Recognition and discrimination of gases by the oxygen-sensing signal transducer protein HemAT as revealed by FTIR spectroscopy
Pinakoulaki, Eftychia; Yoshimura, H.; Yoshioka, S.; Aono, S.; Varotsis, Constantinos (2006)The determination of ligand binding properties is a key step in our understanding of gas sensing and discrimination by gas sensory proteins. HemAT is a newly discovered signal transducer heme protein that recognizes O 2 ...
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Resonance Raman detection of a ferrous five-coordinate nitrosylheme b3 complex in cytochrome cbb3 oxidase from Pseudomonas stutzeri
Pinakoulaki, Eftychia; Stavrakis, Stavros; Urbani, A.; Varotsis, Constantinos (2002)Understanding the chemical nature of the nitric oxide (NO) moiety of nitrosylheme copper oxidases is crucial for elucidation of the NO activation process. In the present work, direct resonance Raman spectroscopic observation ...
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Resonance Raman detection of the Fe2+-C-N modes in heme-copper oxidases: A probe of the active site
Pinakoulaki, Eftychia; Vamvouka, M.; Varotsis, Constantinos (2004)Resonance Raman spectroscopy has been employed to investigate the reduced cyano complexes of cytochrome aa3 from bovine heart and Rhodobacter sphaeroides and of cytochrome bo3 from E. coli. In the aa 3-type oxidases, the ...
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Resonance Raman detection of the heme Fe(II)-NO/2-nitrovinyl species in myoglobin
Ioannou, Androulla; Pinakoulaki, Eftychia (2018)The six-coordinate heme Fe(II)-NO/2-nitrovinyl species in myoglobin has been detected and characterized by resonance Raman spectroscopy. The Fe(II)-14NO and 15N-O stretching frequencies of the ferrous heme nitrosyl/2-nitrovinyl ...
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Resonance Raman detection of the myoglobin nitrito heme Fe-O-N=O/2-nitrovinyl species: Implications for helix E-helix F interactions
Lambrou, Alexandra; Pinakoulaki, Eftychia (2015)The description of biological activity in heme proteins responsible for activating small molecules requires identification of ligand movement into the metal and non-metal binding sites. Mechanisms of nitrite reductase ...
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Resonance raman spectroscopy of nitric oxide reductase and cbb3 Heme-Copper oxidase
Pinakoulaki, Eftychia; Varotsis, Constantinos (2008)Elucidating the structure and properties of the active sites in cbf 3 heme-copper oxidase and in nitric oxide reductase (Nor) is crucial in understanding the reaction mechanisms of oxygen and nitric oxide reduction by both ...
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The role of the cross-link His-Tyr in the functional properties of the binuclear center in cytochrome c oxidase
Pinakoulaki, Eftychia; Pfitzner, U.; Ludwig, B.; Varotsis, Constantinos (2002)Resonance Raman and Fourier transform infrared spectroscopies have been used to study the aa3-type cytochrome c oxidase and the Y280H mutant from Paracoccus denitrificans. The stability of the binuclear center in the absence ...
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Simultaneous resonance Raman detection of the heme a3-Fe-CO and CuB-CO species in CO-bound ba3-cytochrome c oxidase from Thermus thermophilus: Evidence for a charge transfer CuB-CO transition
Pinakoulaki, Eftychia; Ohta, T.; Soulimane, T.; Kitagawa, T.; Varotsis, Constantinos (2004)Understanding of the chemical nature of the dioxygen and nitric oxide moiety of ba3-cytochrome c oxidase from Thermus thermophilus is crucial for elucidation of its physiological function. In the present work, direct ...
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Spin Crossover in Nitrito-Myoglobin as Revealed by Resonance Raman Spectroscopy
Lambrou, Alexandra; Ioannou, Androulla; Pinakoulaki, Eftychia (2016)The myoglobin (Mb) heme Fe-O-N=O and heme Fe-O-N=O/2-nitrovinyl species have been characterized by resonance Raman spectroscopy. In the heme Fe-O-N=O species, the bound nitrite ligand is removed by solvent exchange, thus ...
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Spin Crossover in Nitrito‐Myoglobin as Revealed by Resonance Raman Spectroscopy
Lambrou, Alexandra; Ioannou, Androulla; Pinakoulaki, Eftychia (2016)
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Structural dynamics of heme-copper oxidases and nitric oxide reductases: Time-resolved step-scan Fourier transform infrared and time-resolved resonance Raman studies
Pinakoulaki, Eftychia; Koutsoupakis, Constantinos; Stavrakis, Stavros; Aggelaki, Marialena; Papadopoulos, George Angelos; Daskalakis, Vangelis; Varotsis, Constantinos (2005)Of the spectroscopic methods available for the characterization of the dynamics of heme protein active sites, time-resolved resonance Raman spectroscopy (TR3) is a powerful technique because excitation within the heme π-π* ...
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The structure of a ferrous heme-nitro species in the binuclear heme a3/CuB center of ba3-cytochrome c oxidase as determined by resonance Raman spectroscopy
Loullis, Andreas; Noor, M. R.; Soulimane, T.; Pinakoulaki, Eftychia (2015)Members of the cytochrome c oxidase family exhibit nitrite reductase activity. In this work, we have characterized a ferrous heme a3-nitro species in ba3-oxidase by resonance Raman spectroscopy. This provides the first ...
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The structure of the hyponitrite species in a heme Fe-Cu binuclear center
Varotsis, Constantinos; Ohta, T.; Kitagawa, T.; Soulimane, T.; Pinakoulaki, Eftychia (2007)NO laughing matter: The enzymatic production of laughing gas (N 2O) from two molecules of NO requires the formation of the N-N bond and the subsequent cleavage of the N-OH bond. Resonance Raman spectroscopic studies have ...