Electronic spectroscopy proteins

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... 

It is obvious that x-ray cyrstallographic methods will be the final arbiter of the structural features of molybdoproteins, but until such structures are obtained, and even afterwards as far as dynamic features are concerned, spectroscopic methods must be used to gain insight into the nature of these catalysts. Electronic spectroscopy so far has been of little use here since molybdenum complexes in general appear to exhibit broad weak absorptions. In proteins these are always buried under absorptions from hemes, flavins, and iron-sulfur centers. Massey et al., (15) discovered that pyrazolo [3,4-d] pyrimidines will bind Mo (IV) in milk xanthine oxidase that had been reduced with xanthine... 

Even if the calculations were performed on a simple model, the results presented in Figure 8 nicely reflect the structure-electronic spectroscopy relationship between the various types of copper-cysteinate proteins. The copper coordination geometry of axial type 1 proteins is close to trigonal, and their spectroscopic characteristics are reflected by the results obtained for (p > 80°. Rhombic type 1 proteins like pseudoazurin and cucumber basic protein, on the other hand, have (p angles between 70° and 80°. As can be seen from Figure 8, even at such a small... 

The effort that leads to optimization of the particle morphology is largely one of trial and error, and there is no simple means to describe the distribution of components within individual particulates. Clearly, if the majority of an active component (API) is in the interior of a particle, then the dissolution or release characteristics are likely to differ from particles where the API is predominantly on the surface. The surface distribution of proteins and polymers within spray-dried particles has been studied using electron spectroscopy for chemical analysis that involves analyzing the energy signature of electrons scattered from surfaces while being bombarded by x-rays [11,28-31], Conclusions can then be drawn... 

Figure 16. General models for Hg(II) binding to the MerR protein. Mutagenesis studies led to the proposal of model 1 having linear bis coordination with ancillary ligation (173). Studies by electronic spectroscopy and Hg-EXAFS, indicate that Hg(II) is bound by three primary thiolate ligands, consistent with models 2 and 3, above (202, 209). Mutant complementation studies with Bacillus MerR support the model for Hg(II) bound by three primary bonds (83).

Due to the fundamental importance of the adsorbed protein film, many methods have been used to characterize its nature. These methods include ellipsometry (3,A), Fourier transform infrared spectroscopy (FTIR) (5,6), multiple attenuated internal reflection spectroscopy (MAIR) (7,8) immunological labeling techniques (9), radioisotope labeled binding studies (j ), calorimetric adsorption studies (jj ), circular dichroism spectroscopy (CDS) (12), electrophoresis (j ), electron spectroscopy for chemical analysis (ESCA) (1 ), scanning electron microscopy (SEM) (15,16,9), and transmission electron microscopy (TEM) (17-19). 

A new technique has been developed using Electron Spectroscopy for Chemical Analysis (ESCA) (24). This method is based on the surface sensitivity of ESCA, where the analytical depth is about 2 nm, which allows the outer surface to be analysed separately from the bulk of the material. ESCA gives the elemental composition (except hydrogen) which thus allows the user to divide the surface into components of the same number as the number of elements presents (normally three, i.e. protein, carbohydrate and fat). 

See also-. Asbestos. Carbohydrates Dietary Fiber Measured as Nonstarch Poiysaccharides in Riant Foods. Electrophoresis Polyacryiamide Geis. Forensic Sciences DNA Profiling Fibers. Fourier Transform Techniques. Functional Group Analysis. Infrared Spectroscopy Overview. Liquid Chromatography Size-Exclusion. Microscopy Techniques Light Microscopy Scanning Electron Microscopy. Proteins Overview. Textiles Synthetic. X-Ray Absorption and Diffraction Overview. 

Mechanics, Classical Molecular Electronics Photoelectron Spectroscopy Protein Structure Quantum Chemistry Quantum Mechanics... 

Wagner, M S., Horbett, T.A., Castner, D.G. (2003) Characterizing multicomponent adsorbed protein films using electron spectroscopy for chemical analysis, time-of-flight secondary ion mass spectrometry, and radiolabeling capabilities and limitations. Biomaterials, 24, 1897-1908. 

---