What is the Identity of the Metal Ions in the Active Sites of Coenzyme B12-Dependent Diol Dehydratase? A Computational Mutation Analysis

2009 ◽  
Vol 113 (25) ◽  
pp. 8435-8438 ◽  
Author(s):  
Takashi Kamachi ◽  
Masanori Takahata ◽  
Tetsuo Toraya ◽  
Kazunari Yoshizawa
Keyword(s):  
Metal Ions ◽  
Mutation Analysis ◽  
Active Sites ◽  
Coenzyme B12 ◽  
Diol Dehydratase

scholarly journals Homoadenosylcobalamins as probes for exploring the active sites of coenzyme B12-dependent diol dehydratase and ethanolamine ammonia-lyase

FEBS Journal ◽  
2005 ◽  
Vol 272 (18) ◽  
pp. 4787-4796 ◽  
Author(s):  
Masaki Fukuoka ◽  
Yuka Nakanishi ◽  
Renate B. Hannak ◽  
Bernhard Krautler ◽  
Tetsuo Toraya
Keyword(s):  
Active Sites ◽  
Coenzyme B12 ◽  
Diol Dehydratase

Promoted photocarriers transfer and increased active sites for optimal CO2–to–CH4 photoconversion via the modification of atomically dispersed transition metal ions in CdZnS nanocrystals

2021 ◽  
Author(s):  
Haibo Huang ◽  
Hui-Ying Zhang ◽  
Feng-Ying Cai ◽  
Y Li ◽  
Jian Lü ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Conversion Rate ◽  
Active Sites ◽  
Transition Metal Ions ◽  
Co2 Photoreduction

Atomically dispersed transition metal ions doped CdZnS nanocrystals were synthesized to delicately tune the selectivity of CO2 photoreduction towards CH4, by which the CZS–Cu2+ achieved an excellent CO2–to–CH4 conversion rate...

scholarly journals A Review on Metal Ions Modified TiO2 for Photocatalytic Degradation of Organic Pollutants

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1039
Author(s):  
Dafu Jiang ◽  
Tunmise Ayode Otitoju ◽  
Yuanyuan Ouyang ◽  
Noor Fazliani Shoparwe ◽  
Song Wang ◽  
...  
Keyword(s):  
Metal Ions ◽  
Active Sites ◽  
Crystal Surface ◽  
Uv Light ◽  
Photogenerated Electron ◽  
Tio2 Photocatalyst ◽  
Electron Hole ◽  
Visible Light Range ◽  
Low Toxicity ◽  
High Chemical Stability

TiO2 is a semiconductor material with high chemical stability and low toxicity. It is widely used in the fields of catalysis, sensing, hydrogen production, optics and optoelectronics. However, TiO2 photocatalyst is sensitive to ultraviolet (UV) light; this is why its photocatalytic activity and quantum efficiency are reduced. To enhance the photocatalytic efficiency in the visible light range as well as to increase the number of the active sites on the crystal surface or inhibit the recombination rate of photogenerated electron–hole pairs electrons, various metal ions were used to modify TiO2. This review paper comprehensively summarizes the latest progress on the modification of TiO2 photocatalyst by a variety of metal ions. Lastly, the future prospects of the modification of TiO2 as a photocatalyst are proposed.

scholarly journals Modified ion exchange jackfruit seeds resin for removal of selected trace heavy metal ions from aqueous solution

2021 ◽  
Vol 2 (2) ◽  
pp. 84-92
Author(s):  
S N Ndung’u ◽  
E W Nthiga ◽  
R N Wanjau
Keyword(s):  
Heavy Metal ◽  
Ion Exchange ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Active Sites ◽  
Ion Exchange Resin ◽  
Standard Entropy ◽  
Environmentally Sustainable ◽  
Heavy Metal Ions Removal ◽  
Metal Ions Removal

Water is essential for every life processes. However, its quality is deteriorating every day due to the recent industrial advancements. Anthropogenic processes such as industrialization, mining and agricultural activities have led to alarming discharge of heavy metal ions to the aquatic bodies. This possess a greater threat to human, animal and the entire ecosystem wellbeing. Accumulation of heavy metal ions in drinking water beyond permissible limits is detrimental to human health. Therefore, their removal is paramount. Conventional remediation techniques have been employed but have remained expensive and not universally appropriate. This has therefore spurred research interests in the use of adsorption techniques from locally available materials as an environmentally sustainable alternative. Jackfruit seeds are discarded as wastes of a Jackfruit and can be utilized as an ion exchange resin in heavy metal ions removal from wastewater. The present study involved application of previously prepared raw and modified Jackfruit seed resins to study thermodynamics of copper (II), lead (II) and cadmium (II) ions adsorption from synthetic water. FTIR results showed presence of functional groups in raw and modified resins as important sites for studying thermodynamics of adsorption of copper (II), lead (II) and cadmium (II) ions. Thermodynamic data showed that standard Gibb’s free energy () values for all metals were negative indicating that adsorption process was feasible and favourable. Standard enthalpy change (), standard entropy () and activation energy () were positive (> 40 kJ mol-1) and in the order lead (II) > copper (II) > cadmium (II). This confirmed adsorption of copper (II), lead (II) and cadmium (II) ions onto both raw and modified resins was predominated by chemical interactions between the metal ions and the resin active sites. This was confirmed by very low values of sticking probability (S*). The findings indicated that ion exchange Jackfruit seeds resin is promising for heavy metal ions removal from wastewater in an optimized temperature controlled system.

Metallo-oxidase Enzymes: Design of their Active Sites

2011 ◽  
Vol 64 (3) ◽  
pp. 231 ◽  
Author(s):  
Zhiguang Xiao ◽  
Anthony G. Wedd
Keyword(s):  
Metal Ions ◽  
Active Sites ◽  
Specific Binding ◽  
Large Family ◽  
Outer Sphere ◽  
Transition Metal Ions ◽  
Substrate Oxidation ◽  
Cellular Functions ◽  
Domains Of Life ◽  
Low Valent

Multi-copper oxidases are a large family of enzymes prevalent in all three domains of life. They couple the one-electron oxidation of substrate to the four-electron reduction of dioxygen to water and feature at least four Cu atoms, traditionally divided into three sites: T1, T2, and (binuclear) T3. The T1 site catalyzes substrate oxidation while a trinuclear cluster (comprising combined T2 and T3 centres) catalyzes the reduction of dioxygen. Substrate oxidation at the T1 Cu site occurs via an outer-sphere mechanism and consequently substrate specificities are determined primarily by the nature of a substrate docking/oxidation (SDO) site associated with the T1 Cu centre. Many of these enzymes ‘moonlight’, i.e. display broad specificities towards many different substrates and may have multiple cellular functions. A sub-set are robust catalysts for the oxidation of low-valent transition metal ions such as FeII, CuI, and MnII and are termed ‘metallo-oxidases’. They play essential roles in nutrient metal uptake and homeostasis, with the ferroxidase ceruloplasmin being a prominent member. Their SDO sites are tailored to facilitate specific binding and facile oxidation of these low-valent metal ions and this is the focus of this review.

Mechanism-based Inactivation of Coenzyme B12-dependent Diol Dehydratase by 3-Unsaturated 1,2-Diols and Thioglycerol

2008 ◽  
Vol 144 (4) ◽  
pp. 437-446 ◽  
Author(s):  
T. Toraya ◽  
N. Tamura ◽  
T. Watanabe ◽  
M. Yamanishi ◽  
N. Hieda ◽  
...  
Keyword(s):  
Coenzyme B12 ◽  
Diol Dehydratase

2 Metal Ions at Enzyme Active Sites

The Enzymes ◽  
1992 ◽  
pp. 63-94 ◽  
Author(s):  
Joseph J. Villafranca ◽  
Thomas Nowak
Keyword(s):  
Metal Ions ◽  
Active Sites ◽  
Enzyme Active Sites
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