The possibility of humic acids acting as micellar phase in micellar electrokinetic chromatography was evaluated. We investigated the separation of naphthalene in capillary electrophoresis using various samples of humic acids as micellar phase under different pH conditions, concentrations of humic acid, and temperature. The humic acid samples studied were from different origins including peat, vermicompost and a commercial sample acquired from Aldrich. Methanol was used as a marker for the electroosmotic flow. The results indicate that the formation of micelle depends on the number and nature of the hydrophobic association sites in an aqueous humic acid solution and on the origin and concentration of the humic acid at a defined pH. At lower pH values, the possibility of the humic acid molecule forming pseudomicelles increases due to a combination of neutralized and dissociated charged sites.

Behavior of humic acid as a micellar phase in micellar electrokinetic chromatography (MEKC)

The M2 protein of the influenza A ViruS is a homotetrameric transmembrane proton channel implicated in several stages of the viral replication process. Each of its 97residue monomers is known to include a transmembrane a-helix. but the structures of the Nand C-terminal domains have not yet been solved. A significant barrier to an atomic level understanding of the M2 protein is the difficulty associated with expression and purification of the full-length protein. which has primarily been studied in the form of truncated constructs covering the amphipathic helix and a short C-terminal segment. This C-terminal segment. which includes residues 46-62. has been shown for a truncated version of the protein to consist of an amphipathic helix lying on the membrane surface. Here. we present SDSL-EPR structural studies using full-length M2 constructs to examine sites 50-54 in the proposed amphipathic helix region of M2. Using power saturation data for the protein reconstituted into vesicles and CW spectra of M2FL in detergent micelles and in vesicles. we present a preliminary structure for this region in the full-length protein and compare these results to analogous data collected for truncated M2 constructs. These spectra suggest that this region forms an amphipathic helix in the full-length protein. as has been proposed for the truncated form. with slightly reduced mobility and possibly a more deeply membrane-buried position relative to the truncation. We also find that mobility across this region is severely constrained when either the fulllength or the truncated protein is solubilized into neutral octyl glucoside micelles. though the truncated form is known to remain highly mobile in micelles of zwitterionic detergents. From these results. we suggest that the chemical nature of amphiphile head groups dictates association of the C-terminal domain with the membrane mimic surface.

SDSL-EPR Structural Studies of the Cytoplasmic Helix in Novel Full-Length Constructs of the Influenza A M2 Protein

*e-mail: biaggio@ufscar.br Current address: Departamento de Química Analítica, Instituto de Química de Araraquara, Universidade Estadual Paulista Júlio de Mesquita Filho, Rua Prof. Francisco Degni 55, 14800-060 Araraquara-SP, Brazil A New, Friendlier Methodology to Determine the Average Manganese Valence in LixMn2O4 Spinels Using Atomic Absorption Spectrometry and Molecular Absorption Spectrophotometry

/pdf/a-new-friendlier-methodology-to-determine-the-average-5fv4wohno4.pdf

A New, Friendlier Methodology to Determine the Average Manganese Valence in LixMn2O4 Spinels Using Atomic Absorption Spectrometry and Molecular Absorption Spectrophotometry

The aim of this project is to study the potential of biomass resource available in the
country for use in biohydrogen production. The objectives of the research project are to
characterize different biomass sources based on biomass properties. The biomass
properties being studied are moisture content, calorific value, elemental composition, ash
content, volatile matter content and fixed carbon content. In general, two main analyses
are conducted: Ultimate and Proximate analysis. The main equipments to be used are
CHNS Analyzer, Moisture Analyzer, Bomb Calorimeter and Thermal Gravimetric
Analyzer. The study consists of a series of experiments and analysis relating to the
properties of the biomass samples to look into the prospect for biohydrogen production.
Biomass means any plant-derived organic matter available on a renewable basis. Biomass
is basically organic material cultivated energy crops derived from agriculture or woodbased
operations to produce solid, liquid or gaseous fuels. Biohydrogen is the process of
producing hydrogen from biological processes or biomass. Biohydrogen production has
become an important study since it is known that fossil fuels resources in the world is
depleting at ahigh rate. The analysis would help characterize different biomass samples
for the purpose of biohydrogen production and help realize the potential of biohydrogen
production in the country.

J. Shea

Papers

Analytical Instrumentation Handbook, 3rd Edition - [Book Review]