Blue electrons

Blue copper electron transfer proteins, 6,712-717 Blue copper oxidases, 6,699 Blue copper proteins, 2, 557 6, 649 Blue electron transfer proteins, 6,649,652 spectroscopy, 6, 651 Blue oxidases copper, 6,654,655 Blueprint process, 6,124 Blue proteins model studies, 6,653 Boleite... 

Spectroscopic studies on blue electron-transfer proteins 651... 

Copper is also present in a number of small proteins, characterized by an intense blue colour, that catalyze the transfer of electrons. These blue electron-transfer proteins will be discussed in this section, while attention will be drawn, in summary, to the important structural aspects of the active sites of the copper proteins associated with the biochemistry of dioxygen. 

This is the copper centre responsible for the deep blue colour of the blue oxidases and the blue electron-transfer proteins. Type 1 copper centres have an intense absorption band near 600 nm,... 

Scheme 12.16 Cytochrome P-450-mimic microreactor based on a Pt filled vesicle. (MBox/red = methylene blue electron carrier, oxidised and reduced forms, respectively.)...

As the focus of this review is on copper-dioxygen chemistry, we shall briefly summarize major aspects of the active site chemistry of those proteins involved in 02 processing. The active site structure and chemistry of hemocyanin (He, 02 carrier) and tyrosinase (Tyr, monooxygenase) will be emphasized, since the chemical studies described herein are most relevant to their function. The major classes of these proteins and their origins, primary functions, and leading references are provided in Table 1. Other classes of copper proteins not included here are blue electron carriers [13], copper-thiolate proteins (metallothioneines) [17], and NO reductases (e.g., nitrite [NIR] [18] or nitrous oxide [19]). 

Copper ions in the (I) and (II) oxidation states are biologically important. Basically, three different types of copper centre are shown. Blue of type I copper occurs in the blue electron carrying proteins such as stellacyanin, plastocyanin and azurin. There is also non-blue or type II copper and a type III copper centre that is non-detectable by EPR, apparently containing a pair of contiguous copper atoms. Tyrosinase is a type III protein that is not detected EPR because of antiferromagnetism of a pair of copper in it [137],... 

The electrostatic potential map (EPM) of methyllithium is shown at left. The blue (electron-poor) color of the metal results from its partial positive charge, and the red (electron-rich) color of the methyl group shows its partial negative charge. 

Figure 2.3 la) Methanol, CH3OH, has a polar covalent C-0 bond, arid b) methyl-lithium, CH3Li, has a polar covalent C—Li bond. The computer-generated representations, called electrostatic potential maps, use color to show calculated charge distributions, ranging from red lelectron-rich 5 ) to blue (electron-poor 5 + ),... 

Kozik, M. Baker, L. C. W. Blue Electron Distributions in Diamagnetic Reduced Heteropolytungstates. Insights Concerning Conduction Pathways and Spin Coupling Patterns. 183W NMR Chemical Shift Calculations. In Polyoxometalates from Platonic Solids to Anti-retroviral Activity Pope, M. T. Muller, A., Eds. Kluwer Academic Publishers Dordrecht, 1994, pp 191-202. 

Tn recent years the investigation of ionic processes has become one of the main efforts in radiation chemistry. The existence of the blue electrons predicted by Platzmans theory (17) has been confirmed in different irradiated materials, and their properties and reactions have been extensively studied. This progress in our knowledge about the radiation-induced ionic processes arises mainly from the use of pulse radiolysis, flash photolysis, and matrix isolation techniques. 

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