Structure of the lipid moiety of the Leishmania donovani lipophosphoglycan

The lipid moiety of the lipophosphoglycan of Leishmania donovani had been isolated and characterized as a novel lyso-alkylphosphatidylinositol. Treatment of lipophosphoglycan with either 10% NH4OH or a phosphatidylinositol-specific phospholipase C from Staphylococcus aureus liberated a monoalkylglycerol substituent. Structural characterization of the monoalkylglycerol by gas-liquid chromatography-mass spectrometry indicated the presence of two saturated, unbranched hydrocarbons: a C24 alkyl chain comprising 78% of the lipid with the remaining 22% as a C26 alkyl chain. Periodate sensitivity demonstrated that the alkyl side chain is linked to the C-1 position of the glycerol backbone. Treatment of lipophosphoglycan with nitrous acid released 1-O-alkylglycerophosphorylinositol due to an unacetylated glucosamine residue linked to the inositol of the lyso-alkylphosphatidylinositol. Quantitative analysis of the organic solvent-soluble product of nitrous acid deamination of lipophosphoglycan confirmed the expected ratio of inositol:phosphate:1-O-alkylglycerol as 1:1:1. These results suggest that L. donovani anchors its lipophosphoglycan with a unique lipid component.     

Structural characterization of a novel class of glycophosphosphingolipids from the protozoan Leptomonas samueli.

Aqueous phenol extraction of the lower trypanosomatid Leptomonas samueli released into the aqueous layer a chloroform/methanol/water-soluble glycophosphosphingolipid fraction. Alkaline degradation and purification by gel filtration chromatography resulted in a tetrasaccharide (phosphatidylinositol (PI)-oligosaccharide A), and a pentasaccharide (PI-oligosaccharide B), each containing 2 mol of 2-aminoethylphosphonate and 1 mol of phosphate. Nuclear magnetic resonance spectroscopy and fast atom bombardment-mass spectrometry suggested that the structure of PI-oligosaccharide A is [formula: see text] and that of PI-oligosaccharide B is as shown. [formula: see text] Both compounds contain an inositol unit linked to ceramide via a phosphodiester bridge. The major aliphatic components of the ceramide portion are stearic acid, lignoceric acid, and C20-phytosphingosine. These novel glycolipids fall within the glycosylated phosphatidylinositol (GPI) family, since they contain the core structure Man alpha (1-->4)GlcNH2 alpha (1-->6)myo-inositol-1-PO4, which is also found in the glycoinositolphospholipids and lipophosphoglycan of Leishmania spp., the L. major promastigote surface protease, the glycosylphosphatidylinositol anchor of Trypanosoma brucei variant surface glycoprotein, and the lipopeptidophosphoglycan of Trypanosoma cruzi. The glycophosphosphingolipids of Leptomonas have features in common with the glycolipids of both Leishmania and T. cruzi, resembling the former by the alpha (1-->3) linkage of mannose to the GPI core, while the 2-aminoethylphosphonate substituent on O-6 of glucosamine and the presence of ceramide in place of glycerol lipids is more reminiscent of T. cruzi. Thus these data lend some support to the hypothesis that both T. cruzi and Leishmania evolved from a Leptomonas-like ancestor.     

Structural variation in the glycoinositolphospholipids of different strains ofTrypanosoma cruzi

The structures of the glycoinositolphospholipids (GIPLs) from five strains of the protozoan parasiteTrypanosoma cruzi have been determined. Two series of structures were identified, all but one containing the same Man₄(AEP)GlcN-Ins-PO₄ core. Series 1 oligosaccharides are substituted at the third mannose distal to inositol (Man 3) by ethanolamine-phosphate or 2-aminoethylphosphonic acid, as are some glycosyl-phosphatidylinositol-protein anchors ofT. cruzi. The core can be further substituted by terminal (1–3)-linked -galactofuranose units. In contrast, Series 2 oligosaccharides do not have additional phosphorus-containing groups attached to Man 3, the latter being substituted instead by a single side chain unit of -galactofuranose. Series 1 oligosaccharides are present in all strains (G, G-645, Tulahuen CL, and Y) whereas Series 2 structures are present mainly in CL and Y strains. The lipid moiety in the GIPLs from the G, G-645 and Tulahuen strains is predominantly ceramide, as reported for the Y strain, whilst that from the CL strain is a mixture of ceramide and alkylacylglycerol species. The lipid moiety of the GIPLs, and probably also the phosphoinositol-oligosaccharide structures may play an important immunomodulatory role in infection byT. cruzi.Abbreviations GIPL glycoinositolphospholipid - LPPG lipopeptidophosphoglycan - GPI glycosylphosphatidylinositol - AEP 2-aminoethylphosphonic acid - PI phosphoinositol - GC gas-liquid chromatography - MS mass spectrometry - FAB fast atom bombardment - NMR nuclear magnetic resonance - DQF-COSY double quantum-filtered correlation spectroscopy - TOCSY total correlation spectroscopy - ROESY rotating frame nuclear Overhauser enhancement spectroscopy - EtNP ethanolaminephosphate - HMQC heteronuclear multiple quantum coherence - Man mannose - Galf galactofuranose - GlcN glucosamine - Ins inositol - InsP inositolphosphate - Man 3 third mannose distal to inositol - NOE nuclear Overhauser effect - [M+H]⁺ protonated molecule - [M–H]^– deprotonated molecule - RMM relative molecular mass (monoisotopic)     

Characterization of glycosyl phosphatidylinositol lipids of parasitic protozoans: Leishmania mexicana mexicana promastigotes, Trypanosoma cruzi Peru epimastigotes and Tritrichomonas foetus

Glycosyl phosphatidylinositol lipids of cultured L.mex, mexicana LV732 promastigotes, T. cruzi Peru epimastigotes and Tritrichomonas foetus have been isolated and characterized using metabolic labelling and chromatographic and mass spectrometric (MS) techniques. TLC of the unsaponifiable lipid fractions of L. mex. mexicana and T. cruzi obtained from DEAE Sephadex A-25 followed by Iatrobead column chromatography showed three inositol phosphate-containing lipid components. [3H]myo-inositol, [3H]palmitic acid or H3 32PO4 lipid precursors were incorporated into these three lipid components. Fraction 2 (LM2 and TCP-2) comprises inositol phosphate ceramides. The other two fractions appear to contain mono-O-alkyl and di-O-alkyl glycerol inositol phosphates. Lyso-1-O-alkyl phosphatidylinositols could be cleaved by treatment of PI-specific phosphalipase C. The di-O-alkyl-phospho inositols of these parasites being the first dialkylglycerol lipids reported from eukaryotic membranes raises the possibility of chemotherapy for leishmaniasis and trypanosomiasis based upon functional impairment of alkyl ether lipids. Tritrichomonas foetus contains two major glycophosphosphingolipids, designated TF1 and TF2, which are metabolically labelled with [3H]myo-inositol and H3 32PO4. Both lipids contained ceramides. The major ceramide contains the 18:0 and 18:1 bases and 16:0 N-acyl group. The major glycolipid fraction (TF1) contains fucose linked to inositol diphosphate; one of the phosphates being linked to the ceramide moiety, and the other to ethanolamine. TF1 appears to be a novel class of glycophosphosphingolipid, which may be a part of a membrane anchor.     

Phospholipids of Entamoeba invadens.

The major phosphoglycerides present in Entamoeba invadens are phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol. Furthermore, three different sphingolipids could be isolated from the amoeba. In addition to sphingomyelin and a phosphonolipid, ceramide phosphonylethanolamine, a previously unknown sphingolipid was present. This sphingolipid contained a long chain base, inositol, and phosphorus in the ratio of 0.97:0.97: 1.0 and could be identified as ceramide phosphorylinositol. The various individual phospholipids showed different rates of turnover. Phosphatidic acid and phosphatidylinositol had, relative to the other phospholipids, a short half-time of about 12 h. Phosphatidylethanolamine and ceramide phosphorylinositol had a half-time of about 24 and 30 h, respectively. The major phospholipid, phosphatidylcholine and also sphingomyelin and phosphatidylserine showed no turnover. In contrast to the phosphoglycerides, the sphingolipid composition of the amoeba cultivated in different media was rather variable, while the total sphingolipid content remained at 21% of the total amount of phospholipids. The amount of ceramide phosphorylinositol was almost doubled in the cells cultivated on the serum-free medium (T), whereas the amount of sphingomyelin and ceramide phosphonylethanolamine decreased. Evidence is presented that these alterations in the sphingolipid composition of E. invadens are related to the amount of unsaturated fatty acids which were present in the culture medium.     

The O-acetylation patterns in the O-antigens of Hafnia alvei strains PCM 1200 and 1203, serologically closely related to PCM 1205

Serological tests revealed immunochemical similarities between the lipopolysaccharides of Hafnia alvei strains PCM 1200, 1203 and 1205. Immunoblotting and ELISA showed cross-reactions between the strains. NMR spectroscopy showed that the O-deacetylated O-specific polysaccharides isolated from lipopolysaccharides of H. alvei strains PCM 1200 and 1203 possessed the same composition and sequence as the O-deacetylated O-specific polysaccharide of H. alvei strain PCM 1205, that is a glycerol teichoic-acid-like polymer with a repeating unit of the following structure: [carbohydrate structure: see text] NMR spectroscopic studies of the polysaccharides concluded that O-3 of the side chain beta-D-GlcpNAc is partially O-acetylated (50-80%) in both investigated strains. In strain PCM 1203 an additional O-acetyl group (50-80%) is linked to O-6 of the chain -->3)-alpha-D-GlcpNAc-(1--> residue. The structural features of the isolated O-specific polysaccharides were also the same as those of the O-specific polysaccharides on the bacterial cells directly observed by the HR-MAS NMR technique.     

Free ceramide, sphingomyelin, and glucosylceramide of isolated rat intestinal cells.

Free ceramide, glucosylceramide, and sphingomyelin were isolated from mature cells of adult rat small intestine. Free ceramide and ceramide cleaved from sphingomyelin by enzymatic hydrolysis were fractionated by thin-layer chromatography on borate-impregnated silica gel plates. Sphingoid bases were characterized by gas-liquid chromatography of aldehydes formed upon periodate oxidation. Fatty acids were quantified as methyl esters. Ceramide structures were confirmed by direct-inlet mass spectrometry. Free ceramide was found to contain two major long-chain bases in nearly equal quantity: sphingosine, mainly linked to palmitic acid, and 4D-hydroxysphinganine associated with C20 to C24 fatty acids, 22% being hydroxylated. Sphinganine occurred as a minor component linked to nonhydroxy fatty acids. Sphingomyelin contained the three long-chain bases and 63% of its ceramide was N-palmitoyl-sphingosine. Mass spectrometry of glucosylceramide confirmed 4D-hydroxyshingamine as the major sphingoid base associated preferentially with longer chain hydroxy fatty acids.     

Effect of glucosphingolipid synthesis inhibitor (PPMP and PDMP) treatment on Tetrahymena pyriformis: data on the evolution of the signaling system

1-Phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) and 1-phenyl-2-palmitoylamino-3-morpholino-1-propanol (PPMP) are structural analogues of ceramide; inhibiting UDP-glucose : ceramide glucosyltransferase. After treatment with these synthetic ceramide analogues the expression of glucosphingolipid decreases, while ceramide and sphingomyelin levels increase in the cells of higher eukaryotes. In the unicellular Tetrahymena pyriformis, treatment with PDMP (10-20 microM) and PPMP (40-80 microM) influenced the synthesis of galactose, glucosamine and mannose-containing lipids. On the whole the amount of these lipids was reduced, but new galactose and glucosamine-containing lipids appeared (the exact structures of these lipids were not characterized). Incorporation of (32)P into phosphatidylethanolamine (PE) and phosphatidic acid (PA) was decreased significantly; however the amount of inositol phospholipids were increased. The incorporation of 3H-serine into phosphatidylserine was abolished, but incorporation into sphingomyelin and ceramide was increased.The cytoskeletal elements (silver line system) were disturbed on the basis of scanning electron microscopic pictures. The TRITC-Con A binding and the morphology of the cells were influenced as revealed by confocal laser scanning microscopic analyses. In contrast to higher eukaryotes, in Tetrahymena the shorter fatty acyl chain variant (PDMP) proved to be more effective in each of the examined parameters, while the longer chain variants (PPMP) had milder activity.     

Sphingolipids in bean leaves (Phaseolus vulgaris)

Phytoglycolipid has been isolated for the first time from plant leaves (Phaseolus vulgaris). The purified product (almost identical with the phytoglycolipid isolated from flax seed) was a ceramide attached through phosphate diester linkage to an oligosaccharide, which consisted of the usual trisaccharide unit (inositol, hexuronic acid, hexosamine) to which were attached mannose, galactose, and arabinose. The major fatty acids were the saturated 2-hydroxy C(22), C(24), and C(26) acids; the major long-chain bases were dehydrophytosphingosine (d-ribo-1,3,4-trihydroxy-2-amino-8-trans-octadecene) (53%) and phytosphingosine (d-ribo-1,3,4-trihydroxy-2-amino-octadecane) (32%). A ceramide and a cerebroside were also isolated. In the ceramide the major fatty acids and the major long-chain bases were the same as in the phytoglycolipid. In the cerebroside, the fatty acid composition was similar to that in the ceramide and phytoglycolipid, but the long-chain bases consisted of dehydrophytosphingosine and phytosphingosine (7:1) with a substantial amount of unidentified long-chain base. The sugar component was glucose.     

Structural studies of an emulsion-stabilizing exopolysaccharide produced by an adhesive, hydrophobic Rhodococcus strain.

The primary structure of an emulsion-stabilizing exopolysaccharide from the adhesive, hydrophobic Rhodococcus strain No. 33 was elucidated by NMR spectroscopy, methylation analyses, periodate oxidation and oligosaccharide analyses. The polysaccharide PS-33 consisted of rhamnose, galactose, glucose and glucuronic acid in molar ratios of 2:1:1:1. The main chain contained 3-substituted alpha-D-glucuronic acid linked to the 3-position at alpha-L-rhamnose, in addition to 3-substituted residues of beta-D-galactose and alpha-D-glucose. The alpha-L-rhamnose of the side chain was linked to position 4 of the galactose. In addition, the polysaccharide was O-acetylated, corresponding to one acetyl group per repeating unit. From the results two structural possibilities could be suggested. As the polysaccharide carries hydrophobic groups (methyl of rhamnose/O-acetyl), it is very likely that these are of general significance for the emulsifying activity of polysaccharides. It also seems to be possible that this polysaccharide is at least partially responsible for the hydrophobic cell surface properties of the Rhodococcus strain No. 33 and it may be involved in hydrophobic interactions when adhering to hydrophobic interfaces.     

Lea-active heptaglycosylceramide, a hybrid of type 1 and type 2 chain, and the pattern of glycolipids with Lea, Leb, X (Lex), and Y (Ley) determinants in human blood cell membranes (ghosts). Evidence that type 2 chain can elongate repetitively but type 1 chain cannot

Two major glycolipids reactive with the monoclonal anti-Lea antibody have been isolated from human blood cell membranes. One component was identified as lactofucopentaosyl(II)ceramide and the other as a ceramide heptassaccharide with the structure described below: (formula; see text) The structure includes the Lea determinant (type 1 chain) linked to lactoneotetraosylceramide (type 2 chain); thus, it is regarded to be a hybrid between type 1 and 2 chain. In addition, a minor component having the thin-layer chromatographic mobility of a ceramide nonasaccharide, which was reactive to anti-Lea antibody, was detected. No other component with a thin-layer chromatographic mobility slower than the above components and reactive to the anti-Lea antibody was detected. In contrast, a series of slowly migrating glycolipids having X (Lex) determinant (Gal beta 1----4(Fuc alpha 1----3)GlcNAc) was detected. A similar series of long chain glycolipids having Y (Ley) determinant (Fuc alpha 1----2Gal beta 1----4(Fuc1----3)GlcNAc) was detected in human blood cells; in contrast, only one major Leb glycolipid was found with the mobility of a ceramide hexasaccharide. No glycolipid with a long carbohydrate chain composed exclusively of type 1 chain was detected. Thus, chain elongation may proceed through type 2 chain, but not through type 1 chain. Lea and X (Lex) haptens are distributed equally among blood group A, B, and O red blood cells, whereas the quantity of Leb and Y (Ley) haptens is much lower in A and B blood cells than in O blood cells.     

Characterization of novel structures of mannosylinositolphosphorylceramides from the yeast forms of Sporothrix schenckii.

Novel structures of glycoinositolphosphorylceramide (GIPC) from the infective yeast form of Sporothrix schenckii were determined by methylation analysis, mass spectrometry and NMR spectroscopy. The lipid portion was characterized as a ceramide composed of C-18 phytosphingosine N-acylated by either 2-hydroxylignoceric acid (80%), lignoceric (15%) or 2,3-dihydroxylignoceric acids (5%). The ceramide was linked through a phosphodiester to myo-inositol (Ins) which is substituted on position O-6 by an oligomannose chain. GIPC-derived Ins oligomannosides were liberated by ammonolysis and characterized as: Manpalpha1-->6Ins; Manpalpha1-->3Manpalpha1-->6Ins; Manpalpha1-->6Manpalpha1-->3Manpalpha1-->3Manpalpha1-->6Ins; Manpalpha1-->2Manpalpha1-->6Manpalpha1-->3Manpalpha1-->3Manpalpha1-->6Ins. These structures comprise a novel family of fungal GIPC, as they contain the Manpalpha1-->6Ins substructure, which has not previously been characterized unambigously, and may be acylated with a 2,3 dihydroxylignoceric fatty acid, a feature hitherto undescribed in fungal lipids.     

A new 6-hydroxy-4-sphingenine-containing ceramide in human skin.

A new ceramide consisting of 6-hydroxysphingosine linked to a non-hydroxyacid was found in human epidermal lipid. This ceramide was sought because its fatty acid and sphingoid moieties are present in other combinations in human epidermal ceramides. To isolate the new ceramide, the mixture of ceramides in human epidermal lipid was first separated into fractions by thin-layer chromatography (TLC), and then each fraction was further purified by TLC after acetylation of all hydroxyl groups. TLC after acetylation revealed that one of the fractions isolated in the first TLC step contained two components, namely, the ceramide consisting of sphingosine linked to an alpha-hydroxyacid and an unknown ceramide. The new ceramide constituted about 9% of the total ceramides, and was shown by NMR spectroscopy to be N-acyl-6-hydroxysphingosine.     

Regulation of phosphatidylinositol:ceramide phosphoinositol transferase in Saccharomyces cerevisiae.

Maximal phosphatidylinositol:ceramide phosphoinositol transferase activity was measured in yeast cells harvested during the exponential phase of growth. The addition of inositol to the growth medium resulted in a twofold increase in IPC synthase activity in cells grown in the presence or absence of exogenous choline. Enzyme activity was not regulated in yeast inositol biosynthesis regulatory mutants by the addition of inositol to the growth medium.     

Ceramides: Branched alkyl chains in the sphingolipid siblings of diacylglycerol improve biological potency

The synthesis of a small number of ceramide analogues containing a combination of linear and highly branched alkyl chains on either the d-sphingosine or the N-acyl core of the molecule is reported. Regardless of location, the presence of the branched chain improves potency relative to the positive control, C2 ceramide; however, the most potent compound (4) has the branched side chain as part of the d-sphingosine core. The induction of apoptosis by 4 in terms of Annexin V binding and DiOC₆ labeling was superior to that achieved with C2 ceramide.     

Molecular structure of the rhamsan-like exocellular polysaccharide RMDP17 from Sphingomonas paucimobilis.

X-Ray diffraction analysis of the sodium salt of the polysaccharide RMDP17, a 2-deoxy rhamsan analog, reveals that it adopts a gellan-like, half-staggered, threefold, left handed, double helix of pitch 57.4 A. The side chain of the branched polymer is hydrogen bonded to the main chain. Sodium ions, linked to the carboxylate groups, promote the association of helices via water molecules. Two helices of opposite polarity occupy a trigonal unit cell of dimensions a=17.6 and c=28.7 A. The packing arrangement displays a series of hydrogen bonds involving main chain and side chain atoms, as well as some water bridges, between the helices.     

Binary mixtures of asymmetric phosphatidylcholines with one acyl chain twice as long as the other

High-resolution differential scanning calorimetry and 31P NMR spectroscopy have been used to study aqueous phosphatidylcholine (PC) dispersions prepared from colyophilized mixtures of C(10):C(22)PC/C(22):C(12)PC of various molar ratios. These two lipid species are highly asymmetric but have a common structural feature; namely, one acyl chain in the fully extended conformation is about twice as long as the other. Our experimental results support two conclusions: (1) These two component lipids are miscible in all proportions in both gel and liquid-crystalline states. This type of system behaves as a nearly ideal mixture. Its calorimetric parameters are those expected on the basis of the mole fraction weighted average of the corresponding parameters for the pure components. (2) The component lipids appear to self-assemble, at T less than Tm, into a mixed interdigitated bilayer in excess water. In a mixed interdigitated bilayer, the short acyl chain of one asymmetric phosphatidylcholine on one side of the bilayer leaflet is apposed with the short acyl chain of another lipid molecule on the other side of the bilayer leaflet, while the longer acyl chain from each of the two leaflets crosses the entire hydrocarbon width of the bilayer. The fundamental packing unit, as well as the dynamic unit describing the axial rotator motion about the bilayer normal for this mixed interdigitated bilayer, is thus a dimer, whereas the packing unit assigned for the noninterdigitated bilayer such as C(16):C(16)PC lamellae is a monomer.     

Novel plasmalogalactosylalkylglycerol from equine brain

A novel galactosylalkylglycerol modified with a long-chain cyclic acetal at the sugar moiety, 3-O-(4'6'-plasmalogalactosyl) 1-O-alkylglycerol, was isolated from equine brain. The presence of cyclic acetal linkage, its linked position, and the length of the acetal chain of the natural plasmalo lipid were determined by proton NMR spectroscopy and fast-atom bombardment;-mass spectrometry, as well as gas chromatography;-mass spectrometry and gas;-liquid chromatography. To identify the isomeric stereostructure of the natural product, the plasmalo derivative was chemically synthesized from 3-O-galactosyl 2-O-acyl 1-O-alkyl glyceride through acetalization after deacylation. As a result, the direction and position of the acetal chain of the natural plasmalo lipid were characterized as an "endo"-type 4',6'-O-acetal derivative linked to galactoside by comparison with the NMR data of the synthesized product. The chain lengths of alkyl and acetal groups were C(14) for the former and C(16) and C(18) for the latter, and those for the latter group were mostly similar to those of plasmalogalactosyl ceramide, which was previously isolated from equine brain.     

Structure of the O-polysaccharide of Pseudomonas syringae pv. delphinii NCPPB 1879(T) having side chains of 3-acetamido-3,6-dideoxy-D-galactose residues

The O-polysaccharide (OPS) was obtained from the lipopolysaccharide of Pseudomonas syringae pv. delphinii NCPPB 1879(T) and studied by sugar and methylation analyses, Smith degradation, and (1)H- and (13)C-NMR spectroscopy. The OPS was found to contain residues of L-rhamnose (L-Rha) and 3-acetamido-3,6-dideoxy-D-galactose (D-Fuc3NAc), and the following structure of the major (n = 2) and minor (n = 3) heptasaccharide repeating units of the OPS was established: [carbohydrate structure: see text]. The OPS is distinguished by the presence of oligosaccharide side chains consisting of three D-Fuc3NAc residues that are connected to each other by the (alpha 1-->2)-linkage. The OPS is characterized by a structural heterogeneity due to a different position of substitution of one of the four L-rhamnose residues in the main chain of the repeating unit as well as to the presence of oligosaccharide units with an incomplete side chain.     

Synthesis of glycosylated tuftsins and tuftsin-containing IgG fragment undecapeptide

Syntheses are described of two new tuftsin derivatives containing a 2-acetamido-2-deoxy-D-galactopyranosyl unit alpha- or beta-glycosidically linked to the threonine's hydroxy side chain function and of the glycosylated undecapeptide corresponding to the tuftsin region of the heavy chain of IgG (amino acid sequence 289-299). The glycosylated tuftsins were synthesized by the solution procedure. Fmoc-[Gal NAc(Ac)3 alpha]Thr-OH and Fmoc-[GalNAc(Ac)3 beta]Thr-OH were allowed to react with H-Lys(Z)-Pro-Arg(NO2)-OBzl by the mixed anhydride procedure and the resulting glycosylated tetrapeptides were fully deblocked by catalytic hydrogenation followed by treatment with potassium cyanide, purified by ion exchange chromatography and characterized by analytical HPLC, elemental and amino acid analyses, optical rotation, and proton NMR spectroscopy. Synthesis of the glycosylated undecapeptide was achieved by the continuous flow solid phase procedure on 4-hydroxymethylphenoxyacetyl-norleucyl derivatized Kieselguhr-supported resin. Fmoc-amino acid symmetrical anhydrides or pentafluorophenyl esters, in the presence of N-hydroxybenzotriazole, were used as the acylating agents. To mimic the native sequence of the tuftsin region at the Fc-domain of immunoglobulin G a 2-acetamido-2-deoxy-beta-D-glucopyranosyl unit was N-glycosidically linked to the amide side chain of Asn 297. The glycosylated asparagine residue was introduced as N2-fluorenylmethyloxycarbonyl-N4-(2-acetamido-3,4,6-tri-O-acetyl-2 -deoxy-beta-D - glucopyranosyl)-asparagine pentafluorophenyl ester. After cleavage from the resin the glycopeptide was deprotected, purified by ion exchange chromatography, and characterized by analytical HPLC, amino acid analysis, high voltage electrophoresis, and proton NMR. The conformational features of the glyco-undecapeptide were determined by circular dichroism measurements both in water and in 98% trifluoroethanol. Results of biological assays will be published elsewhere.