Amino acids sediments

Amino Acid Sediment Humic Acid Fulvic Acid Humin... 

Amino Acid Sedimentation Peptide Excess Liposome Excess Composition Equilibnum... 

When the sample is a solid, a separation of the analyte and interferent by sublimation may be possible. The sample is heated at a temperature and pressure below its triple point where the solid vaporizes without passing through the liquid state. The vapor is then condensed to recover the purified solid. A good example of the use of sublimation is in the isolation of amino acids from fossil mohusk shells and deep-sea sediments. ... 

Biomolecule Separations. Advances in chemical separation techniques such as capillary zone electrophoresis (cze) and sedimentation field flow fractionation (sfff) allow for the isolation of nanogram quantities of amino acids and proteins, as weU as the characterization of large biomolecules (63—68) (see Biopolymers, analytical techniques). The two aforementioned techniques, as weU as chromatography and centrifugation, ate all based upon the differential migration of materials. Trends in the area of separations are toward the manipulation of smaller sample volumes, more rapid purification and analysis of materials, higher resolution of complex mixtures, milder conditions, and higher recovery (69). 

BLswas, S. D. (1982). Effect of urea on pH, ammonia, amino acids and lactic acid in the human salivary sediment system incubated with varying levels of glucose. Arch. Oral Biot. 27, 68.3-691. 

The hydrodynamic properties of Ustilago cytochrome c were investigated by Thelander (86). He found the partial specific volume to be 0.721 ml/g and the molecular weight, by sedimentation equilibrium, to be 15,500. The latter value, although higher than that given by summation of the constituent amino acid residues (i.e., 11,877, see Table 3), indicates that the protein is monomeric. 

D. Kaufman, Dating Deep Lake Sediments by Using Amino Acid Racemization in Fossil Ostracodes, Geology, 31, 1049 1052 (2003). 

By use of a crude preparation obtained after the cultivation of Aspergillus niger,104 pectinesterase was purified by repeated chromatography on DEAE-cellulose, using gradient elution. The homogeneity of the product was checked by free electrophoresis, sedimentation analysis, and determination of the N-terminal amino acid (phenylalanine). 

Once the amino acid has been bound to its tRNA, it can pass to the next phase of protein synthesis, involving its interaction with mRNA, which takes place on the ribosome, a molecular machine of enormous complexity. The ribosome of E. coli is a ribonucleoprotein assembly of molecular weight 2700 kDa, and sedimentation constant of 70S9. It is made up of roughly two-thirds RNA and one-third protein, and can be separated into a small (30S) and a large (50S) subunit. The 30S subunit contains 21 proteins and one 16S RNA molecule, while the large subunit has 34 different proteins and two RNA molecules, one 23S and one 5S. Despite its size and complexity, the structure of both ribosomal subunits has been determined to atomic resolution (Figure 4.32), and very recently the atomic structure of the 70S ribosome has been determined at 2.8 A resolution (Selmer et al., 2006). 

Carter, P.W., and R.M. Mitterer. 1978. Amino acid composition of organic matter associated with carbonate and non-carbonate sediments. Geochimica et Cosmochima Acta 58 1231-1238. 

Dauwe, B., and J.J. Middleburg. 1998. Amino acids and hexosamines as indicators of organic matter degradation state in North Sea sediments. Limnology and Oceanography 43 782-798. 

Henrichs, S.M., J.W. Farrington, and C. Lee. 1984. Peru upwelling region sediments near 15°S - II. Dissolved free and total hydrolyzable amino acids. Limnology and Oceanography 29 20-34. 

Whelan, J.K. 1977. Amino acids in surface sediment core of the Atlantic abyssal plain. Geochimica et Cosmochimica Acta 41 803-810. 

H2A Barr body-deficient (Bbd) is an evolutionary relatively young histone variant sharing only about 48% amino acid sequence similarity to H2A. This histone variant appears to be specific for mammals (Chadwick and Willard 2001). As indicated by the name, the transcriptionally inactive and highly condensed X chromosome in female mammals (also known as Barr body ) is depleted for H2A , while this variant is detectable in autosomes and the active sex chromosomes. This observation suggested that H2A is linked to transcriptionally active euchromatin. H2A cofractionates in sedimentation centrifugation with hyper-acetylated histone H4, further corroborating that it associates with transcriptionally active euchromatin. 

Fluxes (mg m d-i) of organic carbon and biochemical classes at 9°N, 5°N, and the equator. Compound class fluxes are in mg of compound, not mg C. The amino acids are present as peptides. Fluxes for net plankton are derived from primary production rates and measurements of biochemical content of net plankton. Fluxes into surface sediments were calculated using the sediment Corg content and accumulation rates and biochemical content measurements. Source From Wakeham, S. G., et al. (1997). Geochimica et Cosmochimica Acta 61, 5363-5369. 

Fig. 2. NAPI facilitates H2A, H2B release from nucleosomes that are on positively coiled DNA (A) but not negatively coiled DNA (B). The positively coiled DNA (6.0 kb) with a superhelical density of + 0.05 and negatively coiled DNA (6.0 kb) with a superhelical density of -0.05 were reconstituted with lysine, arginine-labeled histones H3, H4, H2A, H2B by NaCl dialysis from 2.0 M to 1.2 M to 0.6 M to 0.1 M NaCl over a 14 h period. The samples were incubated with NAPI at 35 °C for 5 min and applied to a 5-20% sucrose/100 mM NaCl/40 mM Tris, pH 7.8 gradient. After sedimentation at 200,000 X g for 5 h, fractions were collected and the distribution of DNA (bottom panel) was determined on agarose gel and the distribution of protein (top panel) on SDS-PAGE followed by fluorography. These data are unpublished observations (V. Levchenko and V. Jackson). The deg-H2A is degraded H2A in which a 15 amino acid peptide of the C terminal has been proteolytically removed. When H2A, H2B is no longer present in a nucleosome, the C terminal region is sensitive to proteolysis [126] from a protease which is a minor contaminate in the NAPI preparation.

The isolation of an SCP protein from rat liver homogenates has also been reported (S2). This protein has been found to be heat-labile, to be detectable only in the liver, and to have a molecular weight of approximately 50,000 daltons by gel filtration (S2) and 28,000 daltons by sedimentation equilibrium (S3). Although the functional properties of the heat-labile SCP (SI) are similar to the heat-stable SCP (R2, R3), these proteins appear to be different. According to Scallen et al. (S3), their SCP preparation resembles chemically serum LDL this based on the similarity in amino acid composition between these two proteins. In the... 

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