Of 34 enzymes capable of synthesizing vinyl sugar ester using glucose and activated fatty acid ester, 2,2,2-trichloroethylbutyrate, in dimethylformamide (DMF), an alkaline protease from Streptomyces ...sp. had the highest transesterification activity. Using this protease and divinyladipate in DMF, 6-O-vinyladipoyl glucose was obtained with a 56% yield.
An active and soluble human beta1,4-galactosyltransferase (beta-GT) was produced in Escherichia coli using a maltose-binding protein fusion system. The purified recombinant beta-GT has a K(m) value ...of 0.035 mM for UDP-galactose and a V(max) of 643 x 10(3) nmol/mg/h. The enzyme catalyzes the transfer of galactose from UDP-galactose to N-linked oligosaccharides. The properties of the purified enzyme were identical to those of bovine milk beta-GT.
We have examined synthesis of sugar branched polymer as a biodegradable material by utilizing natural substances. Biodegradation of a poly(vinyl alcohol) (PV−OH) having sugars and fatty acids was ...observed by a biochemical oxygen demand (BOD) tester using the oxygen consumption method. PV−OH is known as a biodegradable polymer by PV−OH assimilating microbes that are not distributed widely. In this paper, the sugar branched polymers were degraded depending upon the molecular weights, and the polymer having a molecular weight (M n) of 3600 was degraded at 70−80% within 28 days by a soil or an activated sludge without addition of PV−OH assimilating microbes. This is because the proportion of PV−OH main chain in the molecular weight of the polymer is low. PV−OH with low molecular weight can be degraded without PV−OH assimilating microbes. These results indicate that the polymer is completely biodegradable and may have application as a new type of water-soluble material.
Recombinant beta-1,4-galactosyltranferase (beta 1,4-GalT) and alpha-2,6-sialytransferase (alpha 2,6-SiaT) immobilised covalently with activated Sepharose beads were employed for the practical ...synthesis of a trisaccharide derivative, Neu-5Ac alpha(2-->6)Gal beta(1-->4)GlcNAc beta-O-(CH2)6-NH2, on a water-soluble primer having GlcNAc residues through a alpha-chymotrypsin-sensitive linker.
The protease-catalyzed transesterifications between hexoses and divinyladipate were examined. In dimethylformamide hexoses such as d-glucose, d-mannose, d-galactose and α-methyl d-galactoside were ...esterified with divinyladipate by alkaline protease from Streptomyces sp. to give corresponding 6-O-vinyl adipoyl sugars. When the denaturing cosolvent, DMSO, was added to the solvent, galactose was selectively esterified at only the C-2 position.PUBLICATION ABSTRACT
The generation of hydroxyl radicals from poly(6‐O‐vinyladipoyl‐D‐glucose) poly(VAG) in the presence of hydrogen peroxide was detected by oxidation of p‐nitrosodimethylaniline (p‐NDA). Several ...hydroxyl radical scavengers inhibited the reaction, but inhibition by superoxide dismutase (SOD) was low. This suggests that hydroxyl radicals from Harber‐Weiss reaction made relatively small contributions to this reaction, and that the enediol moiety of reducing sugar branches in poly(VAG) reacted with hydrogen peroxide to produce hydroxyl radicals. The polymer degraded to a low molecular weight material after reaction with hydrogen peroxide.
A fast rip-up and reroute algorithm for large scale gate arrays is reported. The algorithm combines 'global' and 'local' rip-up and reroute processes to efficiently eliminate the unconnects ...introduced by an initial routing process. The global process reduces the local wire congestion by ripping up and rerouting global paths. The local process eliminates the unconnects, mainly caused by routing order dependency, by ripping up and rerouting local paths. The effectiveness of our method is demonstrated by our experimental results on industrial sea-of-gates (SOG) circuits and a well-known benchmark circuit.
This paper presents an automatic layout generation system for CMOS uniform height cells with a two-dimensional layout style. The two-dimensional layout style described in this paper is effective with ...such cells as consist of considerably varied sizes of transistors. The proposed system generates a high density layout of such cells. To show the effectiveness of the two-dimensional layout style, we compared cell layouts generated by the proposed system with cell layouts in the traditional one-dimensional layout style, for various cell heights. Moreover, the experimental results show that the generated layouts are comparable in terms of cell area to manual two-dimensional layouts done by skilled layout designers.
We are investigating biodegradable plastics by the utilization of natural polymer materials. Development of new materials derived from mono-, di-, and oligo-saccharide, which are constituents of ...polysaccharide, leads to the effective use of the earths resources. In this experiment, enzymatic synthesis of polymerizable sugar esters and their chemical polymerization reactions were examined. Polymerizable sugar ester could be obtained in high yield catalyzed by Bacillus protease in N, N-dimethylformamide (DMF) which is superior in sugar solubility to other organic solvents. By using azo-initiators, the polymerization reaction was carried out in DMF to give the polymer. Both the polymer and the ester monomer have reducing activity derived from reducing sugar moiety.
A method for synthesizing sequential circuits with testability in the level of state transition table is proposed. The state transition table is augmented by adding extra two inputs so that it ...possesses a distinguishing sequence, a synchronizing sequence, and transfer sequences of short length. By using suitable state assignment codes sequential circuits with shorter test sequences and with fewer gates are realized. Some experimental results for small benchmark circuits are shown.< >
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