Metalloproteins play important roles in biology. They account for about 1/3 of structurally characterized proteins and about 1/2 of all proteins.1 The availability of different metal ions with various redox states, ligands, and geometries about the metal ion allows for fine-tuning of the reactivity of proteins at the highest level. As shown in other sections of this encyclopedia, studies of nat...

Zinc is one of the most important metal ions found in proteins performing specific functions associated with life processes. Coordination geometry of the zinc ion in the active site of the metalloprotein-ligand complexes poses a challenge in determining ligand binding affinities accurately in structure-based drug design. We report here an all atom force field based computational protocol for es...

X-ray damage to protein crystals is often assessed on the basis of the degradation of diffraction intensity, yet this measure is not sensitive to the rapid changes that occur at photosensitive groups such as the active sites of metalloproteins. Here, X-ray absorption spectroscopy is used to study the X-ray dose-dependent photoreduction of crystals of the [Fe(2)S(2)]-containing metalloprotein pu...

Supramolecular mimics of metalloproteins, viz. cytochrome P-450 and ironsulfur proteins are described. The cytochrome P-450 mimic consists of a Mn porphyrin and a Rh complex which are incorporated within a vesicle membrane in water. This system catalyses the reductive activation of molecular oxygen in the epoxidation of alkenes at Mn, with reducing equivalents derived from the simultaneous Rh c...

This paper reports X-ray microtomographic visualization of the microorganism Escherichia coli overexpressing a metalloprotein ferritin. The three-dimensional distribution of linear absorption coefficients determined using a synchrotron radiation microtomograph with a simple projection geometry revealed that the X-ray absorption was homogeneously distributed, suggesting that every E. coli cell w...

BACKGROUND In a biological system, an engineered nanomaterial (ENM) surface is altered by adsorbed proteins that modify ENM fate and toxicity. Thus far, protein corona characterizations have focused on protein adsorption, interaction strength, and downstream impacts on cell interactions. Given previous reports of Ag ENM disruption of Cu trafficking, this study focuses on Ag ENM interactions wit...