Article
Chemistry, Inorganic & Nuclear
Azza A. Hassoon, Attila Szorcsik, Livia Fulop, Zita Papp, Nora May, Tamas Gajda
Summary: Copper(II) complexes of HPH-NH2 (L-1) and HPHPY-NH2 (L-2) peptides were studied as small molecular models of lytic polysaccharide monooxygenases, and their coordination properties were investigated by pH-potentiometry and various spectroscopic techniques. It was found that the coordination properties of these ligands were fundamentally different from those of other non-protected N-terminal HXH-sequences concerning the metal binding ability of amide nitrogens.
DALTON TRANSACTIONS
(2022)
Review
Plant Sciences
Theruvothu Madathil Vandhana, Jean-Lou Reyre, Dangudubiyyam Sushmaa, Jean-Guy Berrin, Bastien Bissaro, Jogi Madhuprakash
Summary: Lytic polysaccharide monooxygenases (LPMOs) are a class of enzymes that can oxidatively cleave glycosidic bonds in carbohydrate polymers, facilitating the depolymerisation of recalcitrant biomasses. In addition to their role in biomass conversion, LPMOs may also play significant roles in fungal and oomycete plant pathogenesis, as well as in mutualistic/commensalism symbiosis. They could also be important in microbial pathogenesis and (micro)organism development.
Article
Chemistry, Multidisciplinary
Jingming Zhao, Ying Zhuo, Daniel E. Diaz, Muralidharan Shanmugam, Abbey J. Telfer, Peter J. Lindley, Daniel Kracher, Takahiro Hayashi, Lisa S. Seibt, Florence J. Hardy, Oliver Manners, Tobias M. Hedison, Katherine A. Hollywood, Reynard Spiess, Kathleen M. Cain, Sofia Diaz-Moreno, Nigel S. Scrutton, Morten Tovborg, Paul H. Walton, Derren J. Heyes, Anthony P. Green
Summary: A protective pathway is identified in the active sites of copper-dependent lytic polysaccharide monooxygenases (LPMOs), which prevents oxidative damage during uncoupled turnover. This pathway involves the formation of transient high-valent intermediates and ferromagnetically coupled copper-tyrosyl radical pairs.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Engineering, Chemical
Pedro Ricardo Vieira Hamann, Milena Moreira Vacilotto, Fernando Segato, Igor Polikarpov
Summary: In this study, a new LPMO from Aspergillus fumigatus was biochemically characterized, showing higher efficiency against amorphous cellulose and pH-dependent regioselectivity. Photoactivation experiments demonstrated that it can be activated by light-stimulated chlorophyllin. Moreover, it can boost cellulose depolymerization in combination with other enzymes.
Article
Biochemistry & Molecular Biology
Thasnim P. Mohammed, Akhila George, Madhuri Priya Sivaramakrishnan, Prabha Vadivelu, Sridhar Balasubramanian, Muniyandi Sankaralingam
Summary: A series of amine and imine-based copper(II) complexes with tridentate ligand donors were synthesized and characterized. Experimental results showed that the imine-based complexes exhibited higher reactivity in the oxidation reaction compared to the amine-based complexes. Theoretical calculations supported these findings.
JOURNAL OF INORGANIC BIOCHEMISTRY
(2023)
Article
Agriculture, Multidisciplinary
Fei Li, Ruijian Shao, Yingzheng Mao, Wen Yu, Hongbo Yu
Summary: In this study, LPMOs were found to efficiently supply H2O2 to DyPs for chitosan functionalization using GA as substrate, achieving a higher grafting ratio than reactions with exogenous H2O2. The GA-chitosan conjugates exhibited lower thermal stability and higher antioxidant activity compared to chitosan. This research provides a green and high-efficiency method for enzymatic cascade reactions in chitosan functionalization with potential applications in H2O2-dependent biocatalytic oxidation reactions.
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Winaki P. Sohtun, Sethuraman Muthuramalingam, Muniyandi Sankaralingam, Marappan Velusamy, Ramasamy Mayilmurugan
Summary: Copper(II) complexes with newer N3O ligands were synthesized and characterized, showing nearly perfect square pyramidal geometry. The complexes exhibited catalytic activity in converting substrates with high yields, following Michaelis-Menten enzymatic reaction kinetics. Studies were conducted in water to simulate enzymatic oxidation conditions.
JOURNAL OF INORGANIC BIOCHEMISTRY
(2021)
Article
Chemistry, Inorganic & Nuclear
Natalija Pantalon Juraj, Tana Tandaric, Vanja Tadic, Berislav Peric, Dominik Moreth, Ulrich Schatzschneider, Anamaria Brozovic, Robert Vianello, Srecko Kirin
Summary: In this study, the coordination properties of ligands were investigated by modifying their side chain structure. The results showed that the length of the aliphatic linker, isomers of the amide group, and the type of chiral terminal group all had an impact on the coordination properties. Additionally, DFT calculations provided insights into the stability of isomers and the potential hydrogen bonding between ligands in a ML2 complex.
DALTON TRANSACTIONS
(2022)
Article
Biochemistry & Molecular Biology
Yucui Liu, Wei Ma, Xu Fang
Summary: In this study, the role of glycine 2 residue in cellulose degradation by TaAA9 LPMOs was investigated using point mutation. The results showed that replacing glycine with threonine or tyrosine changed the H-bonding network and copper coordination geometry, decreased surface charge, weakened TaAA9-substrate interaction, and enhanced TaAA9-product binding. The G2T-TaAA9 and G2Y-TaAA9 variants exhibited reduced copper affinity, oxidative product diversity, substrate binding, enzymatic activity, and synergy with cellulase compared to wild-type TaAA9. This study highlights the crucial role of the investigated residue in AA9 LPMO catalytic activity and suggests a correlation between the electropositivity of copper and AA9 LPMO activity.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Organic
Kaiqian Chen, Milad Zangiabadi, Yan Zhao
Summary: This study reported a synthetic mimic of lytic polysaccharide monooxygenase that can cleave glycosides and alkyl glycosides in aqueous solution with selectivity.
Review
Biochemistry & Molecular Biology
Morten Sorlie, Malene Billeskov Keller, Peter Westh
Summary: In nature, the enzymatic degradation of recalcitrant polysaccharides involves the collaborative action of glycoside hydrolases (GHs) and lytic polysaccharide monooxygenases (LPMOs) through different mechanisms. GHs use a hydrolytic approach, while LPMOs are oxidative. The interplay between LPMOs and GHs can provide rate enhancements and improved degradation of polysaccharides, although the exact magnitude of the enhancements depends on the nature of the specific GH and LPMO. The understanding of this interplay is important for enhancing enzymatic polysaccharide degradation.
ESSAYS IN BIOCHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Jan Hormann, Olga Verbitsky, Xiaoyu Zhou, Beatrice Battistella, Margarete van der Meer, Biprajit Sarkar, Cunyuan Zhao, Nora Kulak
Summary: We synthesized and characterized Cu(ii) complexes CuL1-CuL6 with cyclen-based ligands. The ligands L-1-L-6 comprise different donor sets including S and O atoms. The substitution of N donor atoms with hard donor O atoms leads to efficient oxidative nucleases, but dissociation of the complex upon reduction. We are showing that the rational combination of O and S atoms next to two nitrogen donors within the macrocycle leads to the stabilization of both redox states, resulting in the highest oxidative DNA cleavage activity within this family of cyclen-based Cu(ii) complexes.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Hee Chang Kwon, Da Hyun Lee, Minyoung Yoon, Saira Nayab, Hyosun Lee, Ji Hoon Han
Summary: In this study, four novel Cu complexes with different geometries were synthesized, and their interactions with DNA were investigated. The Cu complexes containing quinoline and pyridine were found to destabilize the DNA structure through minor groove binding and intercalation, respectively. Among them, the Cu2 complex containing quinoline and morpholine exhibited the highest distortion and cleavage efficiency of DNA.
DALTON TRANSACTIONS
(2023)
Article
Biochemistry & Molecular Biology
Liangkun Long, Lu Sun, Dafan Ding, Kaixiang Chen, Qunying Lin, Shaojun Ding
Summary: The two genes encoding lytic polysaccharide monooxygenases (LPMOs) CsLPMO9A and CsLPMO9B were successfully cloned and expressed in Komagataella phaffii. The two enzymes showed synergistic effects with a commercial cellulase cocktail and demonstrated promising potential in industrial bioconversion of lignocellulosic biomass by increasing the release of glucose, cellobiose, and xylose from the substrate.
PROCESS BIOCHEMISTRY
(2021)
Article
Multidisciplinary Sciences
Tetsundo Furuya, Daisuke Nakane, Kenichi Kitanishi, Natsuki Katsuumi, Arshak Tsaturyan, Igor N. Shcherbakov, Masaki Unno, Takashiro Akitsu
Summary: A novel hybrid protein, CuST@lysozyme, composed of a superoxide dismutase-active Cu(II) complex (CuST) and lysozyme, was prepared. Spectroscopic and electrochemical analyses confirmed the binding of CuST to lysozyme. The crystal structure of CuST@lysozyme revealed the binding of the His15 imidazole group of lysozyme to the Cu(II) center of CuST. The combination of CuST with lysozyme did not decrease the superoxide dismutase activity of CuST. Based on various studies, a proposed O-2(-) disproportionation mechanism catalyzed by CuST@lysozyme was discussed.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Inorganic & Nuclear
Sethuraman Muthuramalingam, Karunanithi Anandababu, Marappan Velusamy, Ramasamy Mayilmurugan
INORGANIC CHEMISTRY
(2020)
Article
Chemistry, Inorganic & Nuclear
Larica Pathaw, Duraiyarasu Maheshwaran, Thavasilingam Nagendraraj, Themmila Khamrang, Marappan Velusamy, Ramasamy Mayilmurugan
Summary: A series of copper(I) complexes have been synthesized and characterized, with some of them structurally analyzed using single-crystal X-ray analysis. These complexes exhibit emission properties in the solid-state, but weak emission in solution. Time-dependent density-functional theory calculations indicate charge transfers mainly occur between specific orbitals.
INORGANICA CHIMICA ACTA
(2021)
Article
Biochemistry & Molecular Biology
Winaki P. Sohtun, Sethuraman Muthuramalingam, Muniyandi Sankaralingam, Marappan Velusamy, Ramasamy Mayilmurugan
Summary: Copper(II) complexes with newer N3O ligands were synthesized and characterized, showing nearly perfect square pyramidal geometry. The complexes exhibited catalytic activity in converting substrates with high yields, following Michaelis-Menten enzymatic reaction kinetics. Studies were conducted in water to simulate enzymatic oxidation conditions.
JOURNAL OF INORGANIC BIOCHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Sethuraman Muthuramalingam, Marappan Velusamy, Swati Singh Rajput, Mehboob Alam, Ramasamy Mayilmurugan
Summary: Novel nickel(II) complexes have been synthesized and shown to catalyze the conversion of atmospheric CO2 into organic cyclic carbonates. These complexes exhibit high catalytic efficiency at room temperature and 1 atm pressure, and can selectively convert a wide range of epoxides into cyclic carbonates.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Nanoscience & Nanotechnology
Yakov Shitrit, Maheshwaran Duraiyarasu, Jitendra Kumar, Siva Reddy, Assaf Ya'akobovitz, Yaron S. Cohen, Eran Edri
Summary: This study presents a facile route for coating acid-sensitive supports with functional coatings using thiolate-based precursors. By using bimetallic precursors, thinner Bi nanoplatelets with lower overpotential for CO2 reduction to formate were deposited. A highly conformal coating of graphene foam with Bi nanoplatelets was also obtained, enabling CO2 reduction to formate at a low onset potential.
ACS APPLIED NANO MATERIALS
(2022)
Article
Materials Science, Biomaterials
Maheshwaran Duraiyarasu, S. Senthil Kumaran, Ramasamy Mayilmurugan
Summary: A dual-modal T1-MRI and optical imaging probe, Fe(C12CAT)3, was synthesized and characterized. The probe exhibited enhanced r1-relaxivity upon interaction with human serum albumin, allowing visualization of the acidic pH environment of cells.
ACS BIOMATERIALS SCIENCE & ENGINEERING
(2023)
Article
Chemistry, Inorganic & Nuclear
Sethuraman Muthuramalingam, Marappan Velusamy, Ramasamy Mayilmurugan
Summary: The synthesis and characterization of nickel(II) complexes with different ligands as catalysts for the activation and conversion of atmospheric CO2 and epoxides into cyclic carbonates were carried out. Among them, Catalyst 4 showed the highest efficiency in forming cyclic carbonates with a high yield, representing the most efficient nickel(II)-based catalyst known to date.
DALTON TRANSACTIONS
(2021)
Article
Chemistry, Inorganic & Nuclear
Duraiyarasu Maheshwaran, Thavasilingam Nagendraraj, T. Sekar Balaji, Ganesan Kumaresan, S. Senthil Kumaran, Ramasamy Mayilmurugan
DALTON TRANSACTIONS
(2020)
Article
Chemistry, Inorganic & Nuclear
Sheela Kumari, Sethuraman Muthuramalingam, Ashish Kumar Dhara, U. P. Singh, Ramasamy Mayilmurugan, Kaushik Ghosh
DALTON TRANSACTIONS
(2020)
Article
Chemistry, Physical
Karunanithi Anandababu, Sethuraman Muthuramalingam, Marappan Velusamy, Ramasamy Mayilmurugan
CATALYSIS SCIENCE & TECHNOLOGY
(2020)
Article
Chemistry, Physical
Yifan Sun, Ye Lv, Wei Li, Jinli Zhang, Yan Fu
Summary: In this study, PtRu electrocatalysts were fabricated on carbon paper via cyclic electrodeposition for the electrocatalytic hydrogenation (ECH) of phenol. The Pt3Ru3 catalyst exhibited excellent activity and stability for the conversion of phenol to cyclohexanol at ambient temperature and various current densities. The in situ Raman spectroscopy and kinetic study revealed the hydrogenation mechanism of phenol over Pt3Ru3 in acidic electrolyte, providing an effective electrochemical strategy for the facile construction of durable electrode materials and efficient phenol hydrogenation.
JOURNAL OF CATALYSIS
(2024)
Article
Chemistry, Physical
Amir Shahzad, Khezina Rafiq, Muhammad Zeeshan Abid, Naseem Ahmad Khan, Syed Shoaib Ahmad Shah, Raed H. Althomali, Abdul Rauf, Ejaz Hussain
Summary: Photocatalytic hydrogen production through water splitting is an effective method for meeting future energy demands. In this study, researchers synthesized a 1 % Ag2S/Cu2S co-doped CdZnS catalyst and found that it can produce hydrogen at a higher rate. The co-doping of Ag2S and Cu2S in the CdZnS catalyst showed a synergistic effect, with Ag2S promoting oxidation reactions and Cu2S promoting reduction reactions.
JOURNAL OF CATALYSIS
(2024)