TY - JOUR
T1 - Links between peptides and Mn oxide
T2 - Nano-sized manganese oxide embedded in a peptide matrix
AU - Najafpour, Mohammad Mahdi
AU - Madadkhani, Sepideh
AU - Akbarian, Somayyeh
AU - Zand, Zahra
AU - Hołyńska, Małgorzata
AU - Kompany-Zareh, Mohsen
AU - Tatsuya, Tomo
AU - Singh, Jitendra Pal
AU - Chae, Keun Hwa
AU - Allakhverdiev, Suleyman I.
N1 - Funding Information:
The authors are grateful to the Institute for Advanced Studies in Basic Sciences and the grant from Iran National Science Foundation (INSF). SIA was supported by the grant from the Russian Science Foundation (No: 14-14-00039). TT was supported in part by Grant-in-Aids for Scientific Research (No. 26220801, 18H05177, 17K07453). We thank the ImageJ group (W. S. Rasband, ImageJ, U. S. National Institutes of Health, Bethesda, Maryland, USA, http://imagej.nih.gov/ij/, 1997–2016.) for the software to provide the colored SEM images.
Publisher Copyright:
© 2018 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
PY - 2018
Y1 - 2018
N2 - Herein we report on a poly-peptide/Mn oxide nanocomposite as a model for the water-oxidizing catalyst in Photosystem II. The material is obtained by the reaction of poly-l-tyrosine, Mn(OAc)2·4H2O and KMnO4. HRTEM images of the nanocomposite indicate the presence of nanoparticles dispersed in a poly-l-tyrosine matrix with no crystalline phases. A broad peak at ∼400-550 nm in the UV-visible spectrum is related to Mn oxide formation. X-ray absorption studies suggest that the Mn atoms are in the oxidation state of +IV and a coordination number of around three was obtained for Mn in the structure. The water-oxidizing activity of the material under electrochemical conditions was also investigated. Electrochemical experiments proved the presence of Mn(iv) oxide. Determination of oxygen coupled to electrochemistry revealed the role of poly-l-tyrosine in decreasing the overpotential for water oxidation. In the next step, the interaction of the nanocomposite and imidazole as a model for the tyrosine 161 and histidine 190 residues in Photosystem II was studied with fluorescence spectroscopy using the multivariate curve resolution-alternating least squares method.
AB - Herein we report on a poly-peptide/Mn oxide nanocomposite as a model for the water-oxidizing catalyst in Photosystem II. The material is obtained by the reaction of poly-l-tyrosine, Mn(OAc)2·4H2O and KMnO4. HRTEM images of the nanocomposite indicate the presence of nanoparticles dispersed in a poly-l-tyrosine matrix with no crystalline phases. A broad peak at ∼400-550 nm in the UV-visible spectrum is related to Mn oxide formation. X-ray absorption studies suggest that the Mn atoms are in the oxidation state of +IV and a coordination number of around three was obtained for Mn in the structure. The water-oxidizing activity of the material under electrochemical conditions was also investigated. Electrochemical experiments proved the presence of Mn(iv) oxide. Determination of oxygen coupled to electrochemistry revealed the role of poly-l-tyrosine in decreasing the overpotential for water oxidation. In the next step, the interaction of the nanocomposite and imidazole as a model for the tyrosine 161 and histidine 190 residues in Photosystem II was studied with fluorescence spectroscopy using the multivariate curve resolution-alternating least squares method.
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U2 - 10.1039/c8nj02119h
DO - 10.1039/c8nj02119h
M3 - Article
AN - SCOPUS:85048360817
SN - 1144-0546
VL - 42
SP - 10067
EP - 10077
JO - New Journal of Chemistry
JF - New Journal of Chemistry
IS - 12
ER -