Dalton Transactions Blog

This HOT Article describes a computational study on Zn- and Cu-clusters with relevance for metallothioneins. It  shows promising results that may have important consequences for our understanding of the interaction between metal ions and metallothionein proteins.

Read more for FREE until 31st January 2012 at:

Metallothionein Zn²⁺– and Cu²⁺-clusters from first-principles calculations
Per Greisen, Jakob B. Jespersen and Kasper P. Kepp
Dalton Trans., 2012, Advance Article
DOI: 10.1039/C1DT11785H

Multinary chalcogenides have been synthesised for decades, some of these structures have interesting magnetic, thermoelectric and optical properties. Many contain at least one alkali metal while there are relatively few containing alkaline earths, examples of the latter variety include BaM₄Se₇ (M = Al, Ga) and Ba₅Ga₄Se₁₀.

Jiyong Yao et al. describe in their HOT article the synthesis of the first two members of the alkaline-earth/group XI/group XIII/chalcogen system, which is not only an interesting alkaline earth chalcogenide but also the first reported quaternary arrangement. The analogue Ba₄LiGa₅Se₁₂ was also synthesised and the three new types of structure were fully characterized and the optical properties determined.

To find out more about this Dalton Transactions Hot Article read the full paper which is free to access for 4 weeks.

Ba2AgInS4 and Ba4MGa5Se12 (M = Ag, Li): syntheses, structures, and optical properties
Wenlong Yin, Kai Feng, Dajiang Mei, Jiyong Yao, Peizhen Fu and Yicheng Wu
Dalton Trans., 2012, Advance Article
DOI: 10.1039/C2DT11895E

Enzymes are able to stabilize metal clusters in an accessible and coordinatively unsaturated state, which allows them to control of adsorption and catalysis at the metal cluster site using an organic–ligand approach. However, the structural features that allow enzymes to achieve such high degrees of coordinative unsaturation remain unknown.

Alexander Katz and his group from UC Berkeley make steps towards determining this by making new stable coordinatively unsaturated iridium clusters in solution and finding out the factors that control their stability. The team use calix[4]arene phosphine ligands to stabilize decarbonylated Ir₄ clusters and prevent their aggregation. You can find out whether the groups have solved the enzyme metal cluster puzzle by reading their Hot Article in Dalton Transactions.

The Hot Article is free to access until 31st January 2012:

Stabilization of coordinatively unsaturated Ir4 clusters with bulky ligands: a comparative study of chemical and mechanical effects
Alexander Okrut, Oz Gazit, Namal de Silva, Rita Nichiporuk, Andrew Solovyov and Alexander Katz
Dalton Trans., 2012, DOI: 10.1039/C1DT11734C

Cytochrome P450 are an enzyme superfamily with a diverse range of functions and are particularly interesting in pharmaceutical, bioanalytical and environmental applications. They are able to metabolise drugs, degrade toxins and catalyse reactions for valuable products. Looking for new substrates which are active with P450 is a very active area of research however determining if a new substrate has reacted isn’t always easy.

There are known substrates for Cytochrome P450 BM3 which do not induce a spin shift on the heme iron, making the reaction undetectable by UV-vis. Expensive and time consuming assays with cofactors and LC-MS studies is one option but Gianfranco Gilardi et al. have developed a fluorescence probe which indicates binding for both physiological and non-physiological substrates and can be used to determine dissociation constants.

To find out more read the full Hot Article which is free to access for 4 weeks.

Fluorescence detection of ligand binding to labeled cytochrome P450 BM3
Valentina E. V. Ferrero, Giovanna Di Nardo, Gianluca Catucci, Sheila J. Sadeghi and Gianfranco Gilardi
Dalton Trans., 2012, Advance Article
DOI: 10.1039/C1DT11437A