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PubMed1993

Synthesis and biological activity of [L-hydroxyproline]3-tuftsin analogue and its alpha- or beta-O-D-glucosylated derivatives.

Syntheses are described of the Hyp3-tuftsin analogue and of its derivatives alpha- or beta-O-glycosylated at the side chain function of the hydroxyproline residue. The carbohydrate-free tetrapeptide was prepared by reacting Z-Thr-Lys(Z)-OH with H-Hyp-Arg(NO2)-OBzl by the mixed anhydride procedure. In the synthesis of the alpha-glycosylated analogue the O-glycosyl amino acid was incorporated by reacting Boc-(Glc alpha+beta)Hyp-OH with H-Arg(NO2)-OBzl through the same procedure. The alpha-glucosylated dipeptide was isolated from the diastereomeric mixture, selectively deblocked, and acylated with Z-Thr-Lys(Z)-OH by the mixed anhydride procedure. In the preparation of the beta-glucosylated analogue the BOP procedure was used for reacting Boc-[Glc(Ac)4 beta]Hyp-OH with H-Arg(NO)2-OBzl was well as for the final coupling to tetrapeptide. Removal of protecting groups from crude tetrapeptides was achieved by catalytic hydrogenation. Deacetylation of the sugar moiety of the beta-glucosylated tetrapeptide was achieved by treatment with sodium methoxide in methanol. The synthetic compounds were isolated by ion exchange chromatography, and characterized by elemental analysis, amino acid analysis, optical rotation and proton NMR. Their capacity to evoke the release of interleukin 1 from mouse peritoneal macrophages and to modulate immunogenic activity of antigen-fed cells was evaluated, in comparison with tuftsin and rigin. All of the analogues were found to possess tuftsin-like activity.

Amino Acid Sequence↗
PubMed1994

Synthetic immunochemistry of glycohexapeptide analogues characteristic of oncofetal fibronectin. Solid-phase synthesis and antigenic activity.

Monoclonal antibody FDC-6, and its second-generation antibodies FDB-1 and FDB-4, are able to distinguish between fibronectin (FN) from fetal or cancer tissue (onco-FN) vs. FN from normal adult tissue and plasma (nor-FN). The epitope structure recognized by the above antibodies is the glycohexapeptide H-Val-(GalNAc-alpha)Thr-His-Pro-Gly-Tyr-OH (P2). In order to define further the specificity of the reactive site, we synthesized various glycopeptides based on the unglycosylated hexapeptide sequence (P1) and compared their reactivities with these antibodies. In continuation of our structure-activity relationship studies the (Asn3,Ala5)-glycohexapeptide analogue (P3) was synthesized by a solid-phase procedure. The [Ala(CN)3,Ala5]-glycopeptide (P4), owing to dehydration of the asparagine side chain amide during carboxyl activation of Fmoc-Asn-OH, was also isolated. Fmoc-[GalNAc(Ac)3-alpha]Thr-OH was used for incorporating the glycosylated amino acid residue. For the sake of comparison the epitope P2 and the hexapeptide sequence P1 were also synthesized. The final products were characterized by elemental and amino acid analyses, optical rotation, analytical HPLC, proton NMR and fast-atom bombardment mass spectroscopy. Synthetic analogues were applied to inhibit onco-FN specific MAbs FDB-1, FDB-4 and FDC-6 binding to immobilized onco-FN, and their activities were compared with onco-FN and nor-FN. P2 exhibited an activity similar to that of an intact molecule of onco-FN. Deglycosylation (P1) or replacement of amino acid (P3, P4) greatly reduced activity. Data clearly showed that P2 was the minimal essential structure of the epitope in onco-FN defined by MAbs FDB-1, FDB-4 and FDC-6.(ABSTRACT TRUNCATED AT 250 WORDS)

Alanine↗
PubMed1994

Synthesis and biological activity of some linear and cyclic kinin analogues.

Syntheses are described of some linear and cyclic kinin analogues. Cyclization, by the diphenyl-phosphorazide method, of linear peptides prepared by the solid-phase procedure based on Fmoc chemistry, was used for preparing cyclo-bradykinin and cyclo-kallidin (cyclo-Lys-bradykinin). Removal of the protecting group from the lysine side chain of cyclo-kallidin followed by acylation with the N-terminal sequence of vespulakinin 1 (VSK 1), Fmoc-Thr(tBu)-Ala-Thr(tBu)-Thr(tBu)-Arg(Pmc)-Arg(Pmc)-Gly-OH, by the Bop-HOBt procedure, yielded the protected N epsilon-(1-8 VSK 1)-cyclo-N alpha-kallidin, which was deblocked by acid treatment and purified by semi-preparative HPLC. The diglycosylated 1-8 VSK 1 sequence Boc-Thr(tBu)-Ala-(Gal beta)Thr-(Gal beta)Thr-Arg(Pmc)-Arg(Pmc)-Gly-OH was also synthesized by the solid-phase procedure and used to prepare the N epsilon-[(Gal beta)Thr3, (Gal beta)Thr4, 1-8 VSK 1]-cyclo-N-alpha- kallidin. Peptides and glycopeptides were characterized by amino acid analysis, optical rotation, analytical HPLC and FAB-MS. Preliminary pharmacological experiments showed that the cyclic kinin analogues are much less potent then bradykinin but still show specific bradykinin-like actions that support the hypothesis of the presence of a pharmacophore in the centre of the (brady)kinin molecule.

Amino Acid Sequence↗
PubMed1995

Cyclic analogues of Thr6-bradykinin, N epsilon-Lys-bradykinin and endo-Lys8a-vespulakinin 1.

Syntheses are described of the endo-Lys8a-vespulakinin 1 and of cyclo-Thr6- and cyclo-N epsilon-Lys-bradykinin. The linear peptides covering the entire sequences of endo-Lys8a-VSK-1 and Thr6-BK, and the decapeptide containing all residues constituting Lys-BK, with a Arg-Lys peptide bond involving the epsilon-amino function of lysine, were prepared by the solid-phase procedure based on Fmoc chemistry. Cyclization was carried out by the diphenylphosphorazide method. The amino-terminal octapeptide sequence of vespulakinin 1, Fmoc-Thr(tBu)-Ala-Thr(tBu)-Thr(tBu)-Arg(Pmc)-Arg(Pmc)-Arg(Pmc)-Gly-OH, and its N alpha-Boc-[(Gal beta)Thr3, (Gal beta)Thr4]-analogue, were used to prepare N alpha-(1-8 VSK 1)-cyclo-N epsilon-kallidin and N alpha-[(Gal beta)Thr3, (Gal beta)Thr4, 1-8 VSK 1]-cyclo-N epsilon-kallidin. Peptides and glycopeptides were characterized by amino-acid analysis, optical rotation, analytical HPLC and FAB-MS. Consistent with previous findings, preliminary pharmacological experiments on smooth muscle preparations showed that the cyclic, or partially cyclic, analogues were significatively less potent than the linear ones.

Amino Acid Sequence↗
PubMed1997

Synthesis and biological activities of head-to-tail cyclic bradykinin analogues of varying ring size.

Syntheses of cyclic kinin analogues with different backbone atom numbers are described. Cyclization, by either the O-benzotriazolyl-N,N,N',N'-tetramethyluronium tetrafluoroborate/1-hydroxybenzotriazole/diisopropylethyl amine (TBTU-HOBt-DIPEA) or the diphenylphosphoryl azide (DPPA) procedure of linear peptides prepared by the solid-phase method based on the g-fluorenyl methyloxycarbonyl chemistry, was used for preparing cyclo-Gly-Ile-Ile-Gly-bradykinin, cyclo-Lys-kallidin (cyclo-Lys-Lys-bradykinin) and cyclo-des Arg-bradykinin. Peptides were characterized by amino acid analysis, optical rotation, analytical high-performance liquid chromatography and matrix-assisted laser desorption ionization-time flight mass spectrometry. Pharmacological experiments showed that cyclo-Gly-Ile-Ile-Gly-bradykinin (39 backbone atoms) and cyclo-Lys-bradykinin (30 backbone atoms) are about equipotent, when tested on the relaxation of the isolated rat duodenum preparation. The potency of cyclo-des Arg-bradykinin is at least three orders of magnitude lower. The potency of cyclo-Lys-Lys-bradykinin (33 backbone atoms) is one tenth the activity of bradykinin but about 10 times higher than the potency of the above-mentioned cyclokinins and makes the latter analogue the most potent end-to-end cyclic analogue known currently. The present results, in agreement with data from earlier reports, seem to indicate that the enhancement of the number of backbone atoms in the cyclic kinins first increases and subsequently decreases the potency, whereas a reduction in the atom number from 27 to 24 causes a dramatic decrease in potency.

Animals↗
PubMed1992

Immunochemical and structural characterization of the antigenic polysaccharide from Eubacterium saburreum T18.

An antigenic surface polysaccharide produced by Eubacterium saburreum strain T18, isolated from human dental plaque, was purified from formamide extract of whole cells. Methylation analysis, Smith degradation, optical rotation data and nuclear magnetic resonance spectra demonstrated that the purified antigen was a homopolysaccharide composed of D-glycero-D-galacto-heptose (Hep.) residues. The structure of the repeating unit in the polysaccharide was: -[----6)-[alpha-Hep.furanosyl-(1----4)]-beta-Hep.pyranosyl- (1----6)-[alpha-Hep.furanosyl-(1----2), alpha-Hep.furanosyl-(1----4)]-beta- Hep.pyranosyl-(1-)4----6)-beta-Hep.pyranosyl-(1----. No heptose residues were acetylated. Immunodiffusion reactions in agar gel suggested that the immunodeterminant of the antigenic polysaccharide was D-glycero-D-galacto-heptofuranosyl residues as branched nonreducing terminals.

Antigens, Bacterial↗
PubMed1975

A urinary pentasaccharide in bovine mannosidosis.

Abnormally high amounts of low molecular weight mannose-rich carbohydrate material were found in the urine of an Angus calf with mannosidosis. At least five oligosaccharide fractions were detected by paper chromatography. The most abundant compound was purified by gel chromatography, zone electrophoresis, and two consecutive preparative paper chromatographic steps. The yield was 10 mg/liter of urine. From structural studies including nuclear magnetic resonance spectroscopy, optical rotation, sugar analysis, methylation analysis, and partial enzymatic degradation the following structure was deduced: alpha-D-Manp-(1 leads to 6)-beta-D-Manp-(1 leads to 4)-beta-D-GlcNAcp-(1 leads to 4)-beta-D-GlcNAcp-(1 leads to 4)-D-GlcNAc. This oligosaccharide is distinct from all the oligosaccharides previously described which are excreted by patients with mannosidosis.

Acetylglucosamine↗
PubMed1976

Complexes of poly(adenylic acid) with complementary monomers.

The interaction of a number of potentially complementary monomers with poly(A) has been investigated by equilibrium dialysis, optical rotatory dispersion and ultraviolet absorption measurements. Experiments were conducted at pH 7.0, 0.15 M Na+, where poly(A) exists as a random coil with some degree of base-stacking, and at pH 6.0, 0.15 M Na+, where poly(A) adopts the protonated double-helical acid form structure below 15 degrees C. Binding isotherms show that, at 3.5 degrees C, poly(A) forms a 1 : 1 complex with xanthine at pH 6, and a 2:1 complex at pH 7, while oxoformycin forms a 1:1 complex with poly(A) at both pH 6 and pH 7. Poly(A) forms a complex, tentatively assigned 1:1 stoichiometry, with 8-azaxanthine at pH 6, but no complexing occurs at pH 7. The complexes have been characterized by their optical rotatory dispersion and ultraviolet spectra, their thermal stabilities, and their rates of formation at low temperature. All the complexes are laevorotatory at long wavelengths (greater than 300 nm) and unplex formation at low temperature is a slow process requiring many hours for completion. The complexes of poly(A) with 3-methylxanthine have been reinvestigated and shown to undergo normal helix-coil transitions; the anomalous melting behaviour noted previously [Biopolymers, 10, 21 -- 33 (1971)] has been explained. From a comparison of optical rotatory dispersion spectra, it is concluded that the poly(A) with 3-methylxanthine have similar structures, which are quite different from the structures of the corresponding complexes with 7-methylxanthine. The structures and properties of the poly(A) - monomer complexes are discussed, and compared with those of other polynucleotide - monomer complexes. No significant interaction was observed between poly(A) and hypoxanthine, allopurinol, 6,8-dihydroxypurine, 1-methylxanthine, 9-methylxanthine, theophylline, theobromine or 3,9-dimethylxanthine.

Anti-Bacterial Agents↗
PubMed1976

Cell-wall lipopolysaccharide of the 'Shigella-like' Escherichia coli 0124. Structure of the polysaccharide chain.

From Escherichia coli 0124 two lipopolysaccharide preparations were obtained with phenol/water extraction and cetavlon precipitation. Polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate and chemical analysis showed that the two preparations from E. coli 0124 and the corresponding preparations from Shigella dysenteriae type 3 reacted alike. The O-specific polysaccharide moiety was characterized with proton magnetic resonance spectroscopy, optical rotation and paper electrophoresis. The constituents were determined by gas chromatography and ion-exchange chromatography. The polysaccharide contained glucose (Glc), galactose (Gal), galactosamine (GalN) and 4-O-(1'-carboxyethyl)-D-glucopyranose (glucolactilic acid, GlcLA) in the molar ratios of 1:2:1:1. Glucolactilic acid, which has a structure similar to muramic acid, was first found in Sh. dysenteriae. The polysaccharide from E. coli 0124 and oligosaccharides obtained from it by partial acid hydrolysis were subjected to methylation analysis using the method of combined gas chromatography--mass spectrometry. The results indicated that the pentasaccharide repeating unit of the polysaccharide is (see article). In the polysaccharide the repeating units are joined through galactofuranosidic linkages. This structure is identical with that of the somatic polysaccharide of Sh. dysenterae type 3.

Cell Wall↗
PubMed1977

Cell-wall lipopolysaccharide of the 'Shigella-like' Escherichia coli 058. Structure of the polysaccharide chain.

Two lipopolysaccharide preparations were obtained from Escherichia coli 058 by extraction with 45% aqueous phenol and fractional precipitation with cetyltrimethyl ammonium bromide (Cetavlon). Chemical analysis and polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate showed that the two preparations differed only in the extent of the O-specific polysaccharide moiety. The O-specific polysaccharide was characterized with proton magnetic resonance and infrared spectroscopy, optical rotation and paper electrophoresis. Using gas-liquid chromatography and ion-exchange chromatography, it was shown to contain D-mannose, 2-acetamido-2-deoxy-D-glucose, 3-O-(R-1'-carboxyethyl)-L-rhamnose (rhamnolactylic acid), and O-acetyl groups in the molar ratios of 2:1:1:1. The polysaccharide and oligosaccharides obtained from it were subjected to methylation and chromic acid oxidation. The results obtained indicated that the polysaccharide consists of tetrasaccharide repeating units in which the trisaccharide beta-GlcNAc1 - 4alphaMan-1 - 4(2/3-O-Ac)-Man is substituted at C-3 of the non-acetylated mannose with rhamnolactylic acid. The repeating units are joined through alpha-mannosyl-1 - 3-glucosamine bonds. This structure is identical with that of the cell wall polysaccharide of Shigella dysenteriae type 5.

Carbohydrates↗
PubMed1978

Glucose-containing oligosaccharides in the urine of patients with glycogen storage disease type II and type III.

Patients with glycogen storage disease type II and type III were recently found to excrete increased amounts of a glucose-containing tetrasaccharide DGlcp(alpha1 leads to 6)DGlcp(alpha1 leads to 4)DGlcp(alpha1 leads to 4)DGlc [Lennartson, G., Lundblad, A., Sjöblad, S., Svensson, S. and Ockerman, P.A. (1976) Biomed. Mass Spectrom. 3, 51--54]. In addition to this tetrasaccharide, urine from these patients also contains larger oligosaccharides containing only glucose. From urine of patients with glycogen storage disease type II and type III, three and four oligosaccharides respectively have been isolated. Structural studies including sugar analyses, methylation analyses, partial acid hydrolysis and optical rotation revealed that three compounds were present in the urine of both patients. Their proposed structures or partial structures are as follows: DGlcp(alpha1--6)DGlcp(alpha1--6)DGlcp(alpha1--4)DGlcp(alpha1--4)DGlcp(alpha1--4)DGlc, DGlcp(alpha1--4)DGlcp(alpha1--6)DGlcp(alpha1--6)DGlcp(alpha1--4)DGlcp(alpha1--4)DGlc, and DGlcp(alpha1--6)DGlcp(alpha1--4)DGlcp(alpha1--4)DGlcp(alpha1--4)DGlcp(alpha1--6)DGlcp(alpha1--4)DGlcp(alpha1--4)DGlc. A fourth compound has been partially characterized as a branched heptasaccharide with four (1 leads to 4) linkages and two (1 lead to 6) linkages. Glycogen is possibly the origin of these compounds. However, the number of (1 leads to 6) linkages is higher than expected and may indicate a shorter distance between branches in glycogen than has been generally assumed.

Child↗
PubMed1978

Urinary abnormalities in fucosidosis. Characterization of a disaccharide and two glycoasparagines.

The urinary excretion of fucose-containing material was found to be highly increased in a patient with fucosidosis type 2. Three structurally related compounds, a disaccharide and two glycoasparagines, were isolated from the urine. The isolation procedure included ultrafiltration, gel chromatography on Sephadex G-25, preparative zone electrophoresis and paper chromatography. From structural studies including optical rotation, sugar analysis, methylation analysis, ninhydrin degradation, reduction with lithium aluminium hydride and partial hydrolysis, the following structures were deduced: formula (see text), where Fucp is fucopyranose, Manp is mannopyranose, Galcp is galactopyranose, GlcNAcp is 2-acetamido-2-deoxyglucopyranose and Asn is asparagine. The yields of these compounds were 1.7, 40, and 6 mg/l, respectively. The origin of the disaccharide and the two glycoasparagines is probably the core region of glycoprotein carbohydrate chains.

Asparagine↗
PubMed1979

Increased urinary excretion of free N-acetylneuraminic acid in thirteen patients with Salla disease.

Thirteen severely retarded patients with Salla disease, a new type of lysosomal storage disorder, have been studied biochemically. All patients excreted approximately ten times more free sialic acid than normal individuals. The isolated sialic acid was characterized by paper chromatography, thin-layer chromatography, optical rotation, 13C and 1H nuclear magnetic resonance spectroscopy, and mass spectrometry of its permethylated derivative. The results clearly indicated that the excreted sialic acid was identical to N-acetylneuraminic acid. The main sialylated trisaccharide present in the urine of the patients was identified as 3'-sialyllactose by sugar and methylation analysis. The excreted amounts were found to be within normal range.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1985

Structure of the sidechain of lipopolysaccharide from Pseudomonas syringae pv. morsprunorum C28.

The sidechain of the lipopolysaccharide from the phytopathogen Pseudomonas syringae pv. morsprunorum C28 was shown to be composed of D-rhamnose. Using 1H and 13C-NMR spectroscopy, methylation analysis, Smith degradation and optical rotation data, the repeat unit was found to have the structure: ----3)-D-Rhap-(alpha 1----3)-D-Rhap-(alpha 1----2)-D-Rhap-(alpha 1---- and a degree of polymerization of approximately 70. Attention is drawn to the possible prevalence of D-6-deoxyhexoses in the lipopolysaccharides of plant pathogenic bacteria.

Carbohydrate Conformation↗
PubMed1987

Characterization of a polysaccharide component of lipopolysaccharide from Pseudomonas aeruginosa IID 1008 (ATCC 27584) as D-rhamnan.

Structural studies were carried out on a rhamnose-rich polysaccharide isolated from the O-polysaccharide fraction of lipopolysaccharide in Pseudomonas aeruginosa IID 1008 (ATCC 27584) after destruction of the major O-specific chain by alkaline treatment. The isolated polysaccharide contained rhamnose, 3-O-methyl-6-deoxyhexose, glucose, xylose, alanine, galactosamine and phosphorus in a molar ratio of 67:6.9:4.3:2.1:1.1:1.0:4.1. Data from analysis involving Smith degradation, methylation, 1H-NMR spectroscopy and optical rotation measurement showed that the polysaccharide was built up of three moieties, a rhamnan chain composed of about 70 D-rhamnose residues, the core chain and an oligosaccharide chain comprising 3-O-methyl-6-deoxyhexose, xylose, rhamnose and probably glucose. The repeating unit of the rhamnan chain was indicated to have the following structure:----3)D-Rha(alpha 1----3)D-Rha(alpha 1----2)D-Rha(alpha 1----. This structure is identical with that proposed previously for the repeating unit of the side chain of lipopolysaccharide from plant pathogenic bacteria Pseudomonas syringae pv. morsprunorum C28 [Smith, A.R.W., Zamze, S.E., Munro, S.M., Carter, K. J. and Hignett, R.C. (1985) Eur. J. Biochem. 149, 73-78].

Chromatography, Gel↗
PubMed1987

Structural features of sulfated glycans from the tunic of Styela plicata (Chordata-Tunicata). A unique occurrence of L-galactose in sulfated polysaccharides.

The sulfated polysaccharides in the tunic of Styela plicata occur as three fractions that differ markedly in molecular mass and chemical composition. The high-molecular-mass fraction has a high galactose content and a strong negative optical rotation while the low-molecular-mass fractions have a higher proportion of amino sugars and glucose. The galactose occurs in these polysaccharides entirely in the L-enantiomeric form. Although L-galactose is a constituent of several polysaccharides, this is the first report of sulfated polysaccharides that contain high amounts of L-galactose, and that lack the D enantiomorph of this sugar. Furthermore, the structure of the high-molecular-mass fraction, which is composed mainly of a core of alpha-L-galactopyranose residues, sulfated at position 3, linked glycosidically though position 1----4, and with non-sulfated L-galactopyranose non-reducing end-units, is unique among other previously described sulfated glycans. These data are of considerable interest as they show an unusual example of possible variants of polyanionic glycans with structure function in living tissues.

Animals↗
PubMed1987

Structure of the sidechain of lipopolysaccharide from Erwinia amylovora T.

The sidechain of lipopolysaccharide from Erwinia amylovora T was composed of D-fucose, D-galactose and D-glucose in equimolar proportions. Using NMR spectroscopy, methylation analysis, mass spectrometry, Smith degradation and optical rotation data, the repeat unit was shown to have the following most probable structure: (formula; see text)

Carbohydrate Conformation↗
PubMed1990

The structure of Proteus mirabilis O3 O-specific polysaccharide containing N-(2-hydroxyethyl)-D-alanine.

O-Specific polysaccharide was obtained by mild acid degradation of Proteus mirabilis O3 lipopolysaccharide. The polysaccharide was dephosphorylated with 48% HF to give a linear polysaccharide and an amino acid, N-(2-hydroxyethyl)-D-alanine. The structure of the polysaccharide was determined by methylation, Smith degradation and computer-assisted analysis of the 13C-NMR spectra of original and dephosphorylated polymers and oligomers. The structure of the amino acid was investigated by using 1H and 13C-NMR spectroscopy and mass spectrometry (applied to the acetylated methyl ester derivative). Its absolute configuration was established by comparison of the optical rotation value and CD spectrum of the natural and synthetic product. On the basis of the data obtained, it was concluded that the repeating unit of P. mirabilis O3 O-specific polysaccharide has the following structure: (formula; see text) Removal of the amino acid phosphate substituent significantly decreased serological activity of the O-specific polysaccharide, thus showing the immunodominant role of this group. Serological cross-reactions between P. mirabilis O3 and O27 were demonstrated and tentatively substantiated.

Alanine↗