A laccase-type polyphenol oxidase is excreted by sycamore cells (Acer pseudoplatanus L.) cells. The enzyme has been purified by classical purification techniques. It is a blue copper protein of Mr 97 000, containing 45% carbohydrate and 0.24% copper. This protein consists of one single unit and the copper content corresponds to four copper atoms per protein molecule. The specific activity of th...

The effect of immobilized dye concentration on protein complexation was observed using zonal chromatography. A monomeric protein, octopine dehydrogenase, was retained by a single interaction to a Sepharose CL-6B column containing 11.6 mM immobilized Cibacron blue F3GA. By contrast, a tetrameric protein, lactate dehydrogenase, was retained by the same column by multiple interactions. The degree ...

Under copper limiting growth conditions the methanotrophic bacterium Methylococcus capsulatus (Bath) secrets essentially only one protein, MopE*, to the medium. MopE* is a copper-binding protein whose structure has been determined by X-ray crystallography. The structure of MopE* revealed a unique high affinity copper binding site consisting of two histidine imidazoles and one kynurenine, the la...

Understanding the directionality and sequence of protein unfolding is crucial to elucidate the underlying folding free energy landscape. An extra layer of complexity is added in metalloproteins, where a metal cofactor participates in the correct, functional fold of the protein. However, the precise mechanisms by which organometallic interactions are dynamically broken and reformed on (un)foldin...

copper (ii) phthalocyanine and 2,9,16,23 tetrakis nitro copper (ii) phthalocyaninehas been synthesized respectively from phthalonitrile and 4-nitro phthalonitrile under solvent-free condition using two different catalystsovernanodimensionalzeolites. 4-nitro phthalonitrile synthesized from phthalimide in three steps. the newly prepared compounds have been characterized by ir, uv-vis, 1hnmr and m...

The infrared and electronic absorption spectra of a series of new heteroleptic chelated copper (II) complexes [Cu(diamine)(acac)]X that encompass N,N'-1,6-bis(2-bromophenyl)-2,5-diazahexane (diamine), acetylacetonate (acac) and ClO , BPh , PF and BF (X) were studied. The IR, electronic absorption spectra and 4 4 6 4 the molar conductivity of the newly prepared complexes were presented and discu...

We have coupled hybrid quantum mechanics (density functional theory; Car-Parrinello)/molecular mechanics molecular dynamics simulations to a grand-canonical scheme, to calculate the in situ redox potential of the Cu(2+) + e(-) --> Cu(+) half reaction in azurin from Pseudomonas aeruginosa. An accurate description at atomistic level of the environment surrounding the metal-binding site and finite...