Expression, purification and spectral characterization of p21(Waf1/Cip1)

p21(Waf1/Cip1), best known as a broad-specificity inhibitor of cyclin/cyclin-dependent kinase complexes, can interact with various target proteins, and this ability relies on its structural plasticity. Therefore, studies on the structural properties of p(21) are very important to understand its structure-function relationship. However, detailed studies on its secondary structure and biophysical properties have been comparatively sparse. A human p(21) gene was cloned into the temperature expression vector pBV220 and transformed into Escherichia coli strain JM109.

Removal of Cr(III, VI) by quaternary ammonium and quaternary phosphonium ionic liquids functionalized silica materials

A series of silica-based organic–inorganic hybrid materials were prepared by the sol–gel process for Cr(III) and Cr(VI) adsorption. These silica materials generally had high surface areas, good physical–chemical stability and high thermal stability. Trialkylmethylammonium bis 2,4,4-trimethylpentylphosphinate ([A336][C272]) and trihexyl(tetradecyl)phosphonium bis 2,4,4-trimethylpentylphosphinate (Cyphos IL 104) were explored as porogens to prepare porous silica and as extractants to extract chromium ions. Cyphos IL 104 and [A336][C272] functionalized silica sorbents (SG-2, SG-5) can be effectively used for the removal of Cr(III) and Cr(VI) from aqueous solutions by adjusting pH values, whereas trialkylmethylammonium chloride (Aliquat 336) and bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) functionalized silica sorbents (SG-3, SG-4) can only be used for the removal of the single chromium species, Cr(VI) or Cr(III).

Purification, sequencing and biological activity of polypeptide from velvet antler

The velvet antler polypeptide CNT14 was extracted and purified by gel filtration, ion exchange chromatography and RP C, which showed a single peak in HPLC chromatography and a single band in SDS-PAGE. The molecular weight measured by MALDI/TOF/MS spectrum was 1479. 9028. The polypeptide consisted mostly of Glu, Leu, Val, Pro. The amino acid sequence of the polypeptide was detected with ESI-MS/ MS, and the sequence was E-P-T-V-L-D-E-V-C-L-A-H-G-P. The experiments of biological activity of polypeptide CNT14 in vivo were carried out, and the results show that CNT14 has stimulant effects on the growth of rat HT22 cells. Then we produced the polypeptide CNT14 according the amino acid sequence by solid phase synthesis, confirmed the sequence of the polypeptide to be consistent with the amino acid sequence of polypeptide CNT14 which was separated from the velvet antler.

Purification and structure identification of hyaluronic acid

Polysaccharide produced by mutated strain of Streptococcus zooepidemicus was purified by the procedures including Savage method, quaternary ammonium compound precipitation, DEAE-cellulose(DE52) chromatography and Sephadex G-75 gel filtration. The structure of the purified polysaccharide has been characterized by means of chemical composition analysis, C-13 NMR spectrum, infrared spectrum and circular dichroism (CD). All the results showed that the purified polysaccharide was hyaluronic acid (HA). The single helix conformation of the purified HA was determined by Congo red experiment. The molecular weight of the HA was about 1.16x10(6)D, which was measured by viscosity method.

Column chromatographic purification free synthesis of long-chain monodisperse oligo(1,4-phenyleneethynylene)s: towards large-scale automatic synthesis of molecular wires

A facile, mild and rapid solid phase synthetic route free of column chromatographic purification to the synthesis of soluble monodisperse long-chain oligo(1,4-phenyleneethynylene)s is presented.

Study on the synthesis of mixed oxide La2CuO4 and the effect on the catalytic activity to catalytic removal of NO

The mixed oxide La2CuO4 was synthesized by four different methods and characterized with XRD, BET, TEM and low angle XRD. The effect of the synthetic method on the crystal structure, crystal size, surface area and catalytic activity to NO - CO reaction were studied. The results showed that the samples derived from different methods exhibited different activity to NO-CO reaction, the reason may be that the concentration and type of oxygen defect were different when the synthetic methods were different.

Purification and characterization of L-amino acid oxidase from Agkistrodon blomhoffii ussurensis snake venom of Changbai Mountains

The L-a. a, oxidase of Agkistrodon blomhof fii ussurensis of Changbai Mountains in northeast of China has been separated by using ion-exchange and gel filtration techniques, This enzyme is composed of two subunits, the molecular weight of one subunit is about 36 000, the another is about 57 000, determined by sodium dodecyl sulfate-polyacryamide gel electrophoresis and matrix assisted laser desorption ion/time of flight mass spectrometry, The activity of L-a, a. oxidase determined using L-Leu as substrate. The optimal pH of the enzyme is 4. 5 similar to 5. 5 and 8 similar to 9. The UV-Visible absorption spectrum of L-a, a. oxidase shows the characteristics of flavor-proteins.