No abstract

Abstrzct. When polyethyleneimine (PEI), a water-soluble cationic polymer, was added to solutions of glucose dehydrogenase (GDH) from Bacillus megaterium IWG3 at a molar ratio of PEI to GDH greater than 10, the thermal stability of GDH markedly increased. By addition of PEI, the rate of GDH-catalysed oxidation of flo-glucose increased in a low concentration range of NAD + and NADP + and the Michaelis constants and inhibition constants for both NAD + and NADP + decreased. These results suggested that negatively charged GDH interacts with cationic water-soluble polymers to form conjugates by electrostatic attraction, and also that negatively charged coenzymes are "adsorbed" by the polymers, resulting in enrichment of the coenzymes in the vicinity of GDH. Addition of PEI was also found to be effective for preventing the denaturation of GDH by acrylamide.

No abstract

No abstract

Trifluorovinyl methyl, ethyl, isopropyl and tert-butyl ethers have been prepared. These trifluorovinyl ethers show C=C absorption at such a short wavelength as 5.46∼5.50μ. The methyl and ethyl ethers can be polymerized by free-radical initiators. Halogen addition products of trifluorovinyl- and 1, 2-difluoro-2-chlorovinyl ethers have also been prepared. With α-halo or vinyl ethers, the reactions that are catalyzed by acids, including decomposition, are best interpreted as proceeding through the carbonium ion stabilized by carbonium-oxonium resonance.