Purification and characterization of recombinant murine endostatin in E. coli

Endostatin, a carboxyl-terminal fragment of collagen XVIII is known as an anti-angiogenic agent, that specifically inhibits the proliferation of endothelial cell and the growth of several primary tumor. We report here the purification and characterization of the recombinant murine endostatin (rmEndostatin) which was expressed in a prokaryotic expression system. This rmEndostatin has similar physiochemical properties of yeast-produced recombinant endostatin, and it also specifically inhibits the proliferation and migration of bovine capillary endothelial cells stimulated by basic fibroblast growth factor. The biological activity of rmEndostatin was also shown by its anti-angiogenic ability on the chorioallantoic membrane of chick embryo in vivo. In this article, we demonstrate the refolding and purification of rmEndostatin, expressed using E. coli system, to a biologically active and soluble form. In addition, these results confirm the activity of endostatin as a potent anti-angiogenic agent.     

A novel and efficient alkyl radical trap in aqueous medium

A simple water soluble diselenide derivative 1 shows radical scavenger properties towards alkyl and hydroxyl radicals (k₃ (0°C)=6.8×10⁸ M⁻¹ s⁻¹) in Fenton-type chemistry. The reaction rate between produceded alkyl radicals 2 and the diselenide overwhelms self-termination and halogen transfer reactions.     

SEDIMENTATION ANALYSIS OF DNA PHOTOOXIDIZED IN THE PRESENCE OF THIOPYRONINE

Abstract. Illumination of single-stranded φ×174 phage DNA with visible lightλ > 500 nm) in the presence of the sensitizer thiopyronine results in both chain scissions detectable by velocity sedimentation in neutral medium and in alkali-labile bonds which yield secondary strand breaks after alkaline treatment. Compared with the generation of primary strand breaks, the formation of alkali-labile sites seems to be the predominant reaction.
Photodynamic treatment of homogeneous double-stranded Ta, phage DNA leads to changes in the overall conformation of DNA as revealed by an initial increase of the sedimentation coefficient. The simultaneous occurrence of different effects (decrease of molecular weight, increase of effective DNA flexibility) is particularly evident from changes in the sedimentation coefficient distribution. The fact that both processes influence the sedimentation behaviour questions the common procedure of calculating double-strand break numbers from sedimentation coefficient distributions on the basis of s#-M relations which are valid for intact DNA only.
Photooxidized double-stranded DNA exhibits an increased sensitivity against shear forces.     

Coordination compounds of indium : XXXVI. The direct electrochemical synthesis of neutral and anionic organoindium halides

The electrochemical oxidation of indium metal in cells of the type leads to the formation of RInX₂ compounds; if 2,2′-bipyridine is also present, the products are the adducts RInX₂·bipy (R = CH₃, C₂H₅, C₆H₅, C₆H₅CH₂, C₆F₅; X = Cl, Br, I (not all combinations)). When R′₄NX is present instead of bipy, the products are the salts R′₄N[RInX₃]. The electrochemical oxidation apparently proceeds via the general mechanism discussed previously. Anomalous results with CH₃I or C₂H₅I are discussed in the light of the known solution chemistry of organoindium(III) compounds.     

BIOLOGISCHE WIRKUNGEN PHOTOCHEMISCHER WASSERSTOFFPEROXYDBILDUNG:

Abstract— As previously demonstrated, there is a considerable increase in the photodynamic activity of anthraquinone-sulphonic acid on the addition of ethylene glycol, glycerol and sugars in concentrations of the order of 0.4 M . This system exhibits cytostatic activity. With H₂O₂ at higher concentrations there is also formation of aldehydes in approximately equivalent yields as follows:
R.CH₂OH+Q → QH₂+R.CHO
QH₂+O₂→ Q+H₂O₂
In accordance with the recent results of Warburg this accounts for the fundamental importance of glyceraldehyde in cancer research.
Our results on the irradiation of Proteus vulgaris SG2 in buffered medium with the addition of glycerin to anthraquinone-sulphonic acid show the existence of a similar cytostatic effect. One hour's irradiation with visible light reduces the cell count by about 50 per cent.     

Critical evaluation of additivity schemes for estimating heats of atomization

Additivity schemes for estimating heats of formation and heats of atomization of alkanes and halo- alkanes are scrutinized. A least squares analysis of the heats of atomization of alkanes leads to a revision of the values of the parameters. The improvement in the estimated heats of atomization over the values obtained with parameters previously suggested amounts to at least 100%. The reasons for the deviations from the experimental values are discussed. These parameters can be transfered to haloalkanes. Additional parameters necessary for estimating heats of atomization of haloalkanes are also obtained through least squares analyses.     

Cyanide und Halogene

Ohne Zusammenfassung