Tetsuo Shiba

Purification and cDNA cloning of porcine brain GDP-L-Fuc : N-acetyl-beta-D-glucosaminide alpha1->6fucosyltransferase

GDP-L-Fuc:N-acetyl-β-D-glucosaminide α1→6fucosyltransferase (α1-6FucT; EC 2.4.1.68), which catalyzes the transfer of fucose from GDP-Fuc to N-linked type complex glycopeptides, was purified from a Triton X-100 extract of porcine brain microsomes. The purification procedures included sequential affinity chromatographies on GlcNAcβ1-2Manα1-6(GlcNAcβ1-2Manα1-2)Manβ1-4GlcNAcβ1-4GlcNAc-Asn-Sepharose 4B and synthetic GDP-hexanolamine-Sepharose 4B columns. The enzyme was recovered in a 12% final yield with a 440,000-fold increase in specific activity. SDS-polyacrylamide gel electrophoresis of the purified enzyme gave a major band corresponding to an apparent molecular mass of 58 kDa. The α1-6FucT has 575 amino acids and no putative N-glycosylation sites. The cDNA was cloned in to pSVK3 and was then transiently transfected into COS-1 cells. α1-6FucT activity was found to be high in the transfected cells, as compared with non- or mock-transfected cells. Northern blotting analyses of rat adult tissues showed that α1-6FucT was highly expressed in brain. No sequence homology was found with other previously cloned fucosyltransferases, but the enzyme appears to be a type II transmembrane protein like the other glycosyltransferases.

Total synthesis of escherichia coli lipid A

The first total synthesis of E. coli lipid A (1) is described. The synthetic compound was identical with a natural specimen and exhibited the full endotoxic activity. It was thus conclusively proved by this chemical synthesis that lipid A is the active principle of bacterial endotoxin.

Chemical structure of E. Coli Lipid A: Linkage site of acyl groups in the disaccharide backbone

Abstract The structure of the lipid A component of E. coli lippopolysaccharide was determined by means of chemical and 2D-NMR methods unequivocally to be a glucosamine β(1′-6)-disaccharide 1,4′-diphosphate acylated at the two hydroxyl (positions C-3 and −3′) and the two amino groups.

Chemical structure of escherichia coli lipid A

The chemical structure of E. coli lipid A was elucidated to be 2 by determination of the nature of the individual acyl groups bound to the two hydroxyl groups in positions 3,3′ and the two amino groups of the D-glucosamine disaccharide phosphate backbone.

Hypusine, a new amino acid occurring in bovine brain: Isolation and structural determination

Abstract A new basic amino acid, hypusine, was isolated from the homogenate of bovine brain tissue by ion-exchange column chromatography. The structure of this amino acid was determined to be N 6 -4-amino-2-hydroxybutyl)-2,6-diaminohexanoic acid on the basis of its physical properties involving NMR and mass spectra, as well as chemical degradation including periodate oxidation and reduction with HI and P.

The structure of ancovenin, a new peptide inhibitor of angiotensin I converting enzyme

Abstract The structure of ancovenin, a new peptide inhibitor of angiotensin I converting enzyme, was determined to be a unique tricyclic peptide which comprises sixteen amino acid residues including dehydroalanine and three sulfide amino acids as unusual components.

Structure of de-o-acylated lipopolysaccharide from the escherichia coli re mutant strain F 515

Abstract The structure of the oligosaccharide portion of an E.coli Re lipopolysaccharide was determined as α-KDO-(2→4)-α-KDO-(2→6)-β-GlcN-α(1→6)-α-GlcN, bisphosphorylated at positions 1 and 4′. Taking into account the previous determination of the acylation pattern of the GlcN disaccharide, the total structure of E.coli Re LPS was thus established.

Total synthesis of peptide antibiotic nisin

Abstract Total synthesis of a lanthionine peptide nisin was successfully achieved for the first time by application of new methods for preparations of dehydroalanine and lanthionine moieties, resulting in a confirmation of the proposed structure.

Preparation of novel pyranosyl fluorides of 3-deoxy-D-manno-2-octulosonic acid (KDO) feasible for synthesis of KDO α-glycosides

Abstract α-Ketopyranosyl fluorides, 2 and 3 , of 4,5:7,8-di-O-isopropylidene KDO methyl and benzyl esters were prepared and shown to act as effective glycosyl donors. X-Ray structure analysis of 2 and 1 H NMR study established the boat (B 3,6 ) conformation of the di-O-isopropylidene derivatives of KDO and enabled the assignment of their anomeric configurations.

Minimum structural requirements for encephalitogen and for adjuvant in the induction of experimental allergic encephalomyelitis

Abstract Mycobacteria in the adjuvant used for induction of experimental autoimmune encephalomyelitis (EAE) in guinea pigs can be replaced by synthetic N -acetylmuramyl- l -alanyl- d -isoglutamine. A combination of synthetic encephalitogenic peptides and muramyl dipeptides induces EAE effectively at a dose on the microgram level. In this system, the synthetic heptapeptide, H-Trp-Gly-Ala-Glu-Gly-Gln-Arg-OH, with a sequence identical to those of residues 116 to 122 of the basic protein of human myelin, was the shortest peptide causing EAE. These compounds form a simple system which should be useful in studies on the mechanism of the cell-mediated autoimmune reaction.