C-linked neuraminic acid disaccharide was synthesized in a diastereoselective manner from a sulfone donor and aldehyde acceptor, which was protected as a propargyl ether, through a samarium-mediated coupling reaction. The resulting disaccharide has acetal and phenyl sulfide functional groups that can be easily converted into aldehyde and phenyl sulfone groups by photolysis and oxidation reactio...

An enzyme that catalyzes the reversible hpdroxylation of nicotinic acid to 6-hydroxynicotinic acid has been purified from extracts of a nicotinic acid-fermenting clostridium. The enzyme appears to be a flavin adenine dinucleotidecontaining non-heme iron protein and utilizes triphosphopyridine nucleotide as the ultimate electron acceptor. The purified enzyme also exhibits reduced triphosphopyrid...

Acid-switching of the triplet excited state in rhodamine-C60 dyads was achieved. The rhodamine moiety acts as an acid-activated visible light-harvesting antenna and C60 as the singlet energy acceptor and the spin converter, and production of the triplet state was enhanced in the presence of acid.

The title compound [systematic name: (R)-(-)-2-acet-oxy-2-phenyl-acetic acid], C10H10O4, is a resolved chiral ester derivative of mandelic acid. The compound contains an acetate group and a carb-oxy-lic acid group, which engage in inter-molecular hydrogen bonding, forming chains extending parallel to [001] with a short donor-acceptor hydrogen-bonding distance of 2.676 (2) Å.

It is now established that the biological function of transfer RNA (sRNA) is to accept amino acid at a terminus of the chain, resulting in the formation of aminoacylsRNA,1-3 and to transfer the amino acid from that aminoacyl-sRNA into a polypeptide chain by interacting with messenger RNA on the surface of polyribosomes.4, I A number of indirect observations6-9 suggest that the sites for these r...

Transmembrane pH gradients have previously been shown to induce an asymmetric transmembrane distribution of simple lipids that exhibit weak acid or basic characteristics (Hope, M.J. and Cullis, P.R. (1987) J. Biol. Chem. 262, 4360-4366). In the present study we have examined the influence of proton gradients on the inter-vesicular exchange of stearylamine and oleic acid. We show that vesicles c...

A cell-free assay has been developed for the delivery of influenza virus neuraminidase to the plasma membrane. Two types of postnuclear supernatant, which acted as donor and acceptor of the enzyme, were prepared from baby hamster kidney cells. Donor preparations were obtained from cells infected with influenza virus and containing neuraminidase en route to the plasma membrane. Acceptor preparat...

Several investigators have reported that the activation of amino acids for protein synthesis, i.e. the incorporation of amino acids into soluble ribonucleic acids, is dependent upon the source of both the aminoacyl S-RNA’ synthetases and the S-RNA itself. For example, Rendi and Ochoa (1) reported that aminoacyl S-RNA synthetases from Escherichia coli could not incorporate leucine into yeast or ...