14307-03-0Relevant academic research and scientific papers
Synthesis and PLA2-inhibitory properties of 2(R)-acetamido-alkylphosphomethanols with a variable aggregate anchor.
Kley,von Kiedrowski,Unger,Massing
, p. 261 - 264 (2007/10/03)
Acylamino inhibitors of 14 kDa-PLA2 were synthesized which differ in the moiety that is not bound into the enzyme's active site but immersed in the lipid aggregate when a ternary inhibitory complex is formed. Our results indicate that this part of the inhibitors does not significantly influence inhibitory properties as long the amphiphilic character is retained. So, inhibitory and biophysical properties should be variable independently.
Purification and characterization of D-glucosaminitol dehydrogenase from Agrobacterium radiobacter.
Iwamoto,Sakamoto,Tamura,Mikata,Tanaka
, p. 785 - 791 (2007/10/03)
D-Glucosaminitol dehydrogenase, which catalyzes the conversion of D-glucosaminitol to 3-keto-D-glucosaminitol, was purified to apparent homogeneity from extracts of Agrobacterium radiobacter. This organism has constitutively depressed levels of the enzyme but expression of the enzyme is induced by addition of D-glucosamine to the medium. Purification included ammonium sulfate fractionation and chromatography on columns of DEAE-Sephacel, Octyl-Sepharose CL-4B, and Cellulofine. The purified enzyme migrated as a single band, coinciding with dehydrogenase activities specific for D-glucosaminitol and ethanol, when electrophoresed on a 7.5% polyacrylamide gel at pH 8.0. Electrophoresis on a 12.5% PAGE in the presence of 1% SDS also yielded a single band. The enzyme had an apparent molecular mass of 79 kDa, as measured by the pattern of elution from a column of Cellulofine. The results indicated that the enzyme was a dimer of identical (or nearly identical) subunits of 39.5 kDa. D-Glucosaminitol dehydrogenase required NAD+ as a cofactor and used ethanol as the preferred substrate, as well as aliphatic alcohols with 2 to 4 carbon atoms, D-glucosaminitol, D-glucosaminate, DL-allothreonine, glycerol, and erythritol as additional substrates. In 50 mM Tris-HCl buffer (pH 9.0) at 25 degrees C, the K(m) for D-glucosaminitol, ethanol, and NAD+ were 2.2, 2.0, and 0.08 mM, respectively. The enzyme had a pH optimum of 10 for D-glucosaminitol and 8.5 for ethanol. The enzyme lost substantial activity when treated with pyrazole, with certain reagents that react with sulfhydryl groups and with Zn2+ ion. The various results together suggest that the enzyme exploits different amino acid residues for the dehydrogenation of ethanol and of D-glucosaminitol.
A METHOD FOR REDUCTIVE CLEAVAGE OF N-GLYCOSYLAMIDE CARBOHYDRATE-PEPTIDE BOND
Likhosherstov, Leonid M.,Novikova, Olga S.,Piskarev, Vladimir E.,Trusikhina, Elena E.,Derevitskaya, Varvara A.,Kochetkov, Nikolay K.
, p. 155 - 164 (2007/10/02)
A new, mild method for the splitting of N-linked oligosaccharides from glycoproteins includes treatment of glycoproteins (ovomucoid, flavoprotein, ribonuclease B, hemagglutinin, or transferrin) with 2 M LiBH4 in 25 mM LiOH - 50 mM Li citrate - 70percent aqueous tert-butyl alcohol (5 h, 45 deg C), followed by hydrolysis of the resulting glycosylamine with aqueous acetic acid.The oligosaccharides formed were easily isolated by gel filtration and cation-exchange chromatography in 60-80 percent yields.The reaction was accompanied by the intense reductive cleavage of peptide bonds with formation of amino alcohols, but N-deacetylation of hexosamine was completely excluded.The optimal conditions of this reaction were chosen by use of a model glycopeptide, 2-acetamido-4-O-(2-acetamido-2-deoxy-β-D-glucopyranosyl)-1-N-(4-L-aspartoyl)-2-deoxy-β-D-glucopyranosylamine
