351
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Dong CM, Sun XL, Faucher KM, Apkarian RP, Chaikof EL. Synthesis and characterization of glycopolymer-polypeptide triblock copolymers. Biomacromolecules 2004; 5:224-31. [PMID: 14715030 DOI: 10.1021/bm0343500] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glycopolymer-polypeptide triblock copolymers of the structure, poly(l-alanine)-b-poly(2-acryloyloxyethyl-lactoside)-b-poly(l-alanine) (AGA), have been synthesized by sequential atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP). Controlled free radical polymerization of 2-O-acryloyl-oxyethoxyl-(2,3,4,6-tetra-O-acetyl-beta-d-galactopyranosyl)-(1-4)-2,3,6-tri-O-acetyl-beta-d-glucopyranoside (AEL) by ATRP with a dibromoxylene (DBX)/CuBr/bipy complex system was used to generate a central glycopolymer block. Telechelic glycopolymers with diamino end groups were obtained by end group transformation and subsequently used as macroinitiators for ROP of l-alanine N-carboxyanhydride monomers (Ala-NCA). Gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy analysis demonstrated that copolymer molecular weight and composition were controlled by both the molar ratios of the Ala-NCA monomer to macroinitiator and monomer conversion and exhibited a narrow distribution (Mw/Mn = 1.06-1.26). FT-IR spectroscopy of triblock copolymers revealed that the ratio of alpha-helix/beta-sheet increased with poly(l-alanine) block length. Of note, transmission electron microscopy (TEM) demonstrated that selected amphiphilic glycopolymer-polypeptide triblock copolymers self-assemble in aqueous solution to form nearly spherical aggregates of several hundreds nanometer in diameter. Significantly, the sequential application of ATRP and ROP techniques provides an effective method for producing triblock copolymers with a central glycopolymer block and flanking polypeptide blocks of defined architecture, controlled molecular weight, and low polydispersity.
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Affiliation(s)
- Chang-Ming Dong
- Laboratory for Biomolecular Materials Research, Department of Surgery, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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352
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Abstract
Many biologically active natural products are constrained by macrocyclization and modified with carbohydrates. These two types of modifications are essential for their biological activities. Here we report a chemoenzymatic approach to make carbohydrate-modified cyclic peptide antibiotics. Using a thioesterase domain from the decapeptide tyrocidine synthetase, 13 head-to-tail cyclized tyrocidine derivatives were obtained with one to three propargylglycines incorporated at positions 3-8. These cyclic peptides were then conjugated to 21 azido sugars via copper(I)-catalyzed cycloaddition. Antibacterial and hemolytic assays showed that the two best glycopeptides, Tyc4PG-14 and Tyc4PG-15, have a 6-fold better therapeutic index than the natural tyrocidine. We believe this method will also be useful for modifying other natural products to search for new therapeutics.
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Affiliation(s)
- Hening Lin
- Department of Biological Chemistry and Molecular Pharmacology, Armenise 616, Harvard Medical School, Boston, Massachusetts 02115, USA
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353
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Robinson MA, Charlton ST, Garnier P, Wang XT, Davis SS, Perkins AC, Frier M, Duncan R, Savage TJ, Wyatt DA, Watson SA, Davis BG. LEAPT: lectin-directed enzyme-activated prodrug therapy. Proc Natl Acad Sci U S A 2004; 101:14527-32. [PMID: 15448212 PMCID: PMC521935 DOI: 10.1073/pnas.0303574101] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2003] [Indexed: 12/15/2022] Open
Abstract
Targeted drug delivery to selected sites allows reduced toxicity, enhanced efficiency and interchangeable target potential [Langer, R. (2001) Science 293, 58-59 and Molema, G. & Meijer, D. K. F., eds. (2001) Drug Targeting (Wiley-VCH, Weinheim, Germany)]. We describe a bipartite drug-delivery system that exploits (I) endogenous carbohydrate-to-lectin binding to localize glycosylated enzyme conjugates to specific, predetermined cell types followed by (II) administration of a prodrug activated by that predelivered enzyme at the desired site. The carbohydrate structure of an alpha-L-rhamnopyranosidase enzyme was specifically engineered through enzymatic deglycosylation and chemical reglycosylation. Combined in vivo and in vitro techniques (gamma scintigraphy, microautoradiography and confocal microscopy) determined organ and cellular localization and demonstrated successful activation of alpha-L-rhamnopyranoside prodrug. Ligand competition experiments revealed enhanced, specific localization by endocytosis and a strongly carbohydrate-dependent, 60-fold increase in selectivity toward target cell hepatocytes that generated a >30-fold increase (from 0.02 to 0.66 mg) in protein delivered. Furthermore, glycosylation engineering enhanced the serum-uptake rate and enzyme stability. This created enzyme activity (0.2 units in hepatocytes) for prodrug therapy, the target of which was switched simply by sugar-type alteration. The therapeutic effectiveness of lectin-directed enzyme-activated prodrug therapy was shown through the construction of the prodrug of doxorubicin, Rha-DOX, and its application to reduce tumor burden in a hepatocellular carcinoma (HepG2) disease model.
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Affiliation(s)
- Mark A Robinson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
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354
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Venturi F, Venturi C, Liguori F, Cacciarini M, Montalbano M, Nativi C. A New Scaffold for the Stereoselective Synthesis of α-O-Linked Glycopeptide Mimetics. J Org Chem 2004; 69:6153-5. [PMID: 15373507 DOI: 10.1021/jo049441h] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
alpha-O-Linked glycohomoglutamates are obtained as diastereomerically pure compounds by chemo-, regio-, and stereoselective cycloadditions between glycals and aspartic acid derivatives. The latter constitute orthogonally functionalized scaffolds for glycopeptide mimetics.
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Affiliation(s)
- Francesca Venturi
- Dipartimento di Chimica Organica Ugo Schiff, Università di Firenze, via della Lastruccia, 13 I-50019 Sesto Fiorentino (FI), Italy
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355
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Rendle PM, Seger A, Rodrigues J, Oldham NJ, Bott RR, Jones JB, Cowan MM, Davis BG. Glycodendriproteins: a synthetic glycoprotein mimic enzyme with branched sugar-display potently inhibits bacterial aggregation. J Am Chem Soc 2004; 126:4750-1. [PMID: 15080658 DOI: 10.1021/ja031698u] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The continuing ability of bacteria to resist current antibiotic treatments highlights the need for alternative strategies for inhibiting their pathogenicity. Bacterial attachment is a major factor in infectivity and virulence. This key binding phase of bacteria to any potential host is mediated by adhesin proteins and so these present an attractive therapeutic target for antiinfective blocking strategies. However, the natural ligands to adhesins are large, typically complex molecules that are difficult to mimic with small molecules. We describe here a method that creates precise synthetic mimics of glycoproteins that are designed to bind adhesins. By using protein-degrading enzymes as the basis for these mimics we have created large-molecule protein ligands that inhibit aggregation of pathogenic bacteria at levels greater than a million-fold higher than small-molecule inhibitors of adhesins.
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Affiliation(s)
- Phillip M Rendle
- Department of Chemistry, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
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356
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Wang Y, Sheppard TL. Chemoenzymatic synthesis and antibody detection of DNA glycoconjugates. Bioconjug Chem 2004; 14:1314-22. [PMID: 14624649 DOI: 10.1021/bc034144p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A chemoenzymatic approach for the efficient synthesis of DNA-carbohydrate conjugates was developed and applied to an antibody-based strategy for the detection of DNA glycoconjugates. A phosphoramidite derivative of N-acetylglucosamine (GlcNAc) was synthesized and utilized to attach GlcNAc sugars to the 5'-terminus of DNA oligonucleotides by solid-phase DNA synthesis. The resulting GlcNAc-DNA conjugates were used as substrates for glycosyl transferase enzymes to synthesize DNA glycoconjugates. Treatment of GlcNAc-DNA with beta-1,4-galactosyl transferase (GalT) and UDP-Gal produced N-acetyllactosamine-modified DNA (LacNAc-DNA), which could be converted quantitatively to the trisaccharide Lewis X (LeX)-DNA conjugate by alpha-1,3-fucosyltransferase VI (FucT) and GDP-Fuc. The facile enzymatic synthesis of LeX-DNA from GlcNAc-DNA also was accomplished in a one-pot reaction by the combined action of GalT and FucT. The resulting glycoconjugates were characterized by gel electrophoresis, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), and glycosidase digestion experiments. Covalent modification of the 5'-terminus of DNA with carbohydrates did not interfere with the ability of DNA glycoconjugates to hybridize with complementary DNA, as indicated by UV thermal denaturation analysis. The trisaccharide DNA glycoconjugate, LeX-DNA, was detected by a dual DNA hybridization/monoclonal antibody (mAb) detection protocol ("Southwestern"): membrane-immobilized LeX-DNA was visualized by Southern detection with a radiolabeled complementary DNA probe and by Western chemiluminescence detection with a mAb specific for the LeX antigen. The efficient chemoenzymatic synthesis of DNA glycoconjugates and the Southwestern detection protocol may facilitate the application of glycosylated DNA to cellular targeting and DNA glycoconjugate detection strategies.
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Affiliation(s)
- Yingli Wang
- Department of Chemistry and The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113, USA
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357
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Watt GM, Lund J, Levens M, Kolli VSK, Jefferis R, Boons GJ. Site-specific glycosylation of an aglycosylated human IgG1-Fc antibody protein generates neoglycoproteins with enhanced function. ACTA ACUST UNITED AC 2004; 10:807-14. [PMID: 14522051 DOI: 10.1016/j.chembiol.2003.08.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A range of well-defined IgG glycoforms was prepared by employing a combination of synthetic carbohydrate chemistry and genetic engineering. The key aspect of this methodology is the coupling of thioaldoses with cysteine-containing proteins to give disulfide-linked neoglycoproteins. This technology was applied to the synthesis of a series of synthetic N-glycan thioaldoses which were coupled to an aglycosylated IgG1-Fc fragment, engineered to have Cys-297 in place of glycan-linked Asn (Deltah-Fc N297C). Analysis of the resulting Fc neoglycoproteins by mass spectrometry and trypsin digestion showed that the saccharides were site-selectively incorporated at Cys-297 to full occupancy without affecting other Fc protein disulfides. The neoglycoproteins were tested for their ability to interact with human FcgammaRI by inhibiting superoxide production by gamma-interferon-stimulated U937 cells. The neoglycoproteins displayed enhanced superoxide inhibition relative to aglycosylated Deltah-Fc N297C, where increased glycan size correlated positively with increased inhibition.
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Affiliation(s)
- Gregory M Watt
- Complex Carbohydrate Research Center, The University of Georgia, 220 Riverbend Road, Athens, GA 30602, USA.
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358
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Zhu X, Pachamuthu K, Schmidt RR. Synthesis of NovelS-Neoglycopeptides from Glycosylthiomethyl Derivatives. Org Lett 2004; 6:1083-5. [PMID: 15040728 DOI: 10.1021/ol036186z] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reaction of glycosylthiomethyl azides with amino acid and peptide derivatives containing aspartate and glutamate thio acids gave the corresponding glycosylthiomethyl amides in excellent yields. Another type of neoglycopeptides was obtained via reaction of glycosylthiomethyl bromide with cysteine and homocysteine containing peptide derivatives, thus affording the corresponding S-(glycosylthiomethyl) peptides.
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Affiliation(s)
- Xiangming Zhu
- Universität Konstanz, Fachbereich Chemie, Fach M 725, D-78457 Konstanz, Germany
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359
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Yamamoto N, Sakakibara T, Kajihara Y. Convenient synthesis of a glycopeptide analogue having a complex type disialyl-undecasaccharide. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.02.137] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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360
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Reddy BG, Madhusudanan KP, Vankar YD. Trimethylsilylnitrate−Trimethylsilyl Azide: A Novel Reagent System for the Synthesis of 2-Deoxyglycosyl Azides from Glycals. Application in the Synthesis of 2-Deoxy-β-N-glycopeptides. J Org Chem 2004; 69:2630-3. [PMID: 15049677 DOI: 10.1021/jo0354948] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel reagent system comprising Me(3)SiN(3) and 20 mol % of Me(3)SiONO(2) permits conversion of glycals to 1-azido 2-deoxy sugars in one step in fair to good yields. Galactals offer higher stereoselectivities than do the glucals. Reduction of the azide group with Ph(3)P-H(2)O to amino functionality followed by coupling with amino acids leads to the synthesis of novel 2-deoxy-beta-N-glycopeptides irrespective of the geometry of initial azido sugars. Using this protocol, a new gamma-sugar amino acid derivative is also procured.
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Affiliation(s)
- B Gopal Reddy
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-208 016, India
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361
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Stereospecific synthesis of urea-tethered neoglycoconjugates starting from glucopyranosyl carbamates. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.01.055] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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362
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Bielawska H, Michalska M. A novel and practical synthesis of S-(1- and 2-halogenoalkyl)sugars by reaction of carbohydrate S-(O,O-dialkyl)phosphorodithioates and monothioates with fluoride anion. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2003.12.155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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363
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Zhang Z, Gildersleeve J, Yang YY, Xu R, Loo JA, Uryu S, Wong CH, Schultz PG. A new strategy for the synthesis of glycoproteins. Science 2004; 303:371-3. [PMID: 14726590 DOI: 10.1126/science.1089509] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Posttranslational modifications of proteins regulate many biological processes, including metabolism, signal transduction, and gene expression. The synthetic challenges associated with generating homogeneous populations of selectively modified proteins, however, have hindered detailed studies of the effects of these modifications on protein structure and function. Here, we report an approach to the cotranslational synthesis of selectively glycosylated proteins in which the modified amino acid is genetically encoded. We show that myoglobin containing beta-N-acetylglucosamine (GlcNAc)-serine at a defined position can be expressed in Escherichia coli in good yield and with high fidelity. The beta-GlcNAc moiety can be recognized by a saccharide-binding protein, or subsequently modified with a galactosyltransferase to build more complex carbohydrates. This approach should be generally applicable to other posttranslational modifications such as protein phosphorylation, acetylation, and methylation.
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Affiliation(s)
- Zhiwen Zhang
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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364
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Renaudet O, Dumy P. Chemoselectively template-assembled glycopeptide presenting clustered cancer related T-antigen. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2003.10.126] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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365
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Burger K, Kluge M, Koksch B, Fehn S, Böttcher C, Hennig L, Müller G. Hexafluoroacetone as Protecting and Activating Reagent: A New Approach to O-Glycosides. HETEROCYCLES 2004. [DOI: 10.3987/com-04-s(p)6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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366
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Norris P, A. Akula R, P. Temelkoff D, D. Artis N. Rapid Access to Glucopyranosyl-1,2,3- triazoles via Cu(I)-catalyzed Reactions in Water. HETEROCYCLES 2004. [DOI: 10.3987/com-04-10218] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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367
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Watt GM, Boons GJ. A convergent strategy for the preparation of N-glycan core di-, tri-, and pentasaccharide thioaldoses for the site-specific glycosylation of peptides and proteins bearing free cysteines. Carbohydr Res 2004; 339:181-93. [PMID: 14698875 DOI: 10.1016/j.carres.2003.10.029] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Mammalian glycoprotein biosynthesis produces heterogeneous ranges of proteins that possess the same peptide backbone but differ in the nature and site of glycosylation. This feature has frustrated efforts to develop therapeutic glycoproteins as well as the elucidation of biological functions of individual glycoforms. We have developed an attractive approach to well-defined glycoforms of glycoproteins by oxidative coupling of thioaldoses to cysteine-containing peptides and proteins to give disulfide-linked neoglycoconjugates. To this end, the chemical synthesis di-, tri-, and pentasaccharide N-glycan thioaldoses was undertaken. A convergent approach was used for the preparation of the pentasaccharide containing a 'synthetically difficult' beta-mannoside linkage. This linkage was installed by forming initially the corresponding beta-glucoside-containing pentasaccharide, followed by inversion of configuration at C-2. This approach exploited a levulonyl ester at C-2 of a glucosyl donor, which directed the coupling to give the beta-glucoside exclusively and could be removed selectively using hydrazine acetate without affecting other base-labile functionalities. The resulting alcohol was converted into a triflate, which was displaced by tri-n-butylammonium acetate to give a beta-mannosidic linkage. The trisaccharide N-glycan was prepared in a similar manner. Thioaldoses were prepared by displacing the peracetylated alpha-glycosyl chlorides with thioacetate to give the peracetylated beta-thioacetates, which upon saponification gave the desired compounds. The incubation of molar excesses of chitobiose thioaldose with cysteine-containing glutathione and BSA resulted in the site-specific formation of a disulfide-linked neoglycopeptide and neoglycoprotein, respectively.
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Affiliation(s)
- Gregory M Watt
- Complex Carbohydrate Research Center, University of Georgia, 220 Riverbend Road, Athens, GA 30602, USA
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368
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Shoda SI, Kadokawa JI, Mito M, Takahashi S, Noguchi M. Direct Conversion of 2-Acetamido-2-deoxysugars to 1,2-Oxazoline Derivatives by Dehydrative Cyclization in Water. HETEROCYCLES 2004. [DOI: 10.3987/com-04-10065] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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369
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370
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Zhu X, Haag T, Schmidt RR. Synthesis of an S-linked glycopeptide analog derived from human Tamm-Horsfall glycoprotein. Org Biomol Chem 2003; 2:31-3. [PMID: 14737656 DOI: 10.1039/b311583f] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Direct base catalyzed S-glycosylation of a cysteine and a homocysteine containing peptide with O-acetyl protected bromides in DMF-water solution furnished two glycopeptide fragments. The two glycopeptide fragments were linked to the target glycopeptide with two S-glycosyl residues mimicking a part of Tamm-Horsfall glycoprotein.
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Affiliation(s)
- Xiangming Zhu
- Fachbereich Chemie, Universität Konstanz, Fach M 725, D-78457 Konstanz, Germany
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371
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Kerns RJ, Zha C, Benakli K, Liang YZ. Extended applications and potential limitations of ring-fused 2,3-oxazolidinone thioglycosides in glycoconjugate synthesis. Tetrahedron Lett 2003. [DOI: 10.1016/j.tetlet.2003.09.058] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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372
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Hayes W, Osborn HM, Osborne SD, Rastall RA, Romagnoli B. One-pot synthesis of multivalent arrays of mannose mono- and disaccharides. Tetrahedron 2003. [DOI: 10.1016/j.tet.2003.08.011] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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373
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van Ameijde J, Liskamp RMJ. Synthesis of novel trivalent amino acid glycoconjugates based on the cyclotriveratrylene ('CTV') scaffold. Org Biomol Chem 2003; 1:2661-9. [PMID: 12948190 DOI: 10.1039/b303795a] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The convenient synthesis of novel trivalent amino acid glycoconjugates based on cyclotriveratrylene ('CTV') is described. These constructs consist of the CTV scaffold, three oligoethylene glycol spacers of variable length connected to a glyco amino acid residue which can also be varied. The resulting library of trivalent glycoconjugates can be used for studying multivalent interactions.
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Affiliation(s)
- Jeroen van Ameijde
- Department of Medicinal Chemistry, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, PO Box 80082, 3508 TB Utrecht, The Netherlands
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374
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375
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Sridhar PR, Prabhu KR, Chandrasekaran S. Selective reduction of anomeric azides to amines with tetrathiomolybdate: synthesis of beta-D-glycosylamines. J Org Chem 2003; 68:5261-4. [PMID: 12816487 DOI: 10.1021/jo0266947] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A number of beta-d-glycosyl azide derivatives undergo reduction on treatment with tetrathiomolybdate to produce the corresponding beta-d-glycosylamines exclusively without anomerization under very mild and neutral reaction conditions. Acetyl, allyl, benzoyl, and benzyl protective groups are left untouched under the reaction conditions. An exclusive selectivity in the reduction of anomeric azides is observed, while the C-2 and C-6 azides are left untouched.
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Affiliation(s)
- Perali Ramu Sridhar
- Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, Karnataka, India
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376
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Reddy B, Vankar YD. A convenient synthesis of methyl N-acetyl-α-d-lividosaminide from d-glucal. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)01044-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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377
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New types of glycoconjugates: O-glycosylated, N-glycosylated and O-,N-diglycosylated isoserine derivatives. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)00896-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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378
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Crich D, Vinod AU. Oxazolidinone protection of N-acetylglucosamine confers high reactivity on the 4-hydroxy group in glycosylation. Org Lett 2003; 5:1297-300. [PMID: 12688743 DOI: 10.1021/ol0342305] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] The preparation of a convenient oxazolidinone protected N-acetyl glucosamine 4-OH derivative is reported. This substance exhibits enhanced reactivity as a glycosyl acceptor in a variety of coupling methods, the products of which are converted to the target N-acetylglucosaminyl saccharides under very mild conditions.
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Affiliation(s)
- David Crich
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, USA.
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379
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Vízvárdi K, Kreutz C, Davis AS, Lee VP, Philmus BJ, Simo O, Michael K. Phototransamidation as a Method for the Synthesis ofN-Glycosyl Asparagines. CHEM LETT 2003. [DOI: 10.1246/cl.2003.348] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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380
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Williams Z, Litscher ES, Wassarman PM. Conversion of Ser to Thr residues at the sperm combining-site of mZP3 does not affect sperm receptor activity. Biochem Biophys Res Commun 2003; 301:813-8. [PMID: 12589785 DOI: 10.1016/s0006-291x(03)00044-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Mammalian eggs are surrounded by a thick extracellular coat, the zona pellucida, that is composed of three glycoproteins, called ZP1-3. Sperm recognize and bind to O-linked oligosaccharides attached to Ser-332 and Ser-334 at the sperm combining-site of mouse ZP3 (mZP3). Mutation of either of these Ser residues to a small aliphatic amino acid results in the loss of sperm binding to mZP3 in vitro. Here, we converted both Ser-332 and Ser-334 to Thr residues by site-directed mutagenesis. Recombinant mutant glycoprotein made by stably transfected EC cells was purified and then assayed for its ability to inhibit binding of sperm to ovulated eggs in vitro. Results of these experiments suggest that Thr residues can replace the two evolutionarily conserved Ser residues as acceptors for essential O-linked oligosaccharides at the sperm combining-site of mZP3 without affecting the glycoprotein's sperm receptor activity.
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Affiliation(s)
- Zev Williams
- Brookdale Department of Molecular, Cell and Developmental Biology, Mount Sinai School of Medicine, One Gustave L. Levy Place, New York, NY 10029-6574, USA
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381
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Singh S, Ni J, Wang LX. Chemoenzymatic synthesis of high-mannose type HIV-1 gp120 glycopeptides. Bioorg Med Chem Lett 2003; 13:327-30. [PMID: 12565922 DOI: 10.1016/s0960-894x(02)01025-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A chemoenzymatic approach to the synthesis of glycoforms of HIV-1 gp120 glycopeptides is described. Thus, the high-mannose type glycopeptides [gp120 (336-342)] containing Man(9), Man(6) and Man(5) moieties, respectively, were synthesized in satisfactory yields via transglycosylation to the acetylglucosaminyl peptide, using the recombinant Arthrobacter Endo-beta-N-acetyl-glucosaminidase (Endo-A) as the key enzyme.
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Affiliation(s)
- Suddham Singh
- Institute of Human Virology, University of Maryland Biotechnology Institute, University of Maryland, 725 West Lombard Street, Baltimore, MD 21201, USA
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382
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Dudkin VY, Crich D. A short synthesis of the trisaccharide building block of the N-linked glycans. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)00102-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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383
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384
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Ni J, Singh S, Wang LX. Synthesis of maleimide-activated carbohydrates as chemoselective tags for site-specific glycosylation of peptides and proteins. Bioconjug Chem 2003; 14:232-8. [PMID: 12526713 DOI: 10.1021/bc025617f] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An array of maleimide-activated mono- and oligosaccharides were synthesized to permit site-specific glycosylation of cysteine-containing peptides and proteins. Maleimide-activated monosaccharides, in which the native alpha- or beta-O-glycosidic linkages found for nonreducing terminal sugars of native glycoproteins are preserved, were prepared using 2'-aminoethyl glycosides as the key intermediates. In addition, a native high-mannose type oligosaccharide, Man(9)GlcNAc(2)Asn, was converted into its maleimide-activated form by taking advantage of the existing amino group in the Asn portion. The application of these maleimide-activated carbohydrates was exemplified by the site-specific glycosylation of a 36-mer HIV-1 gp41 peptide, T20, which is a potent inhibitor against HIV infection. The chemoselective ligation was found to be rapid, highly efficient, and essentially quantitative. Tagging the biologically active peptide with a mannose and/or oligomannose moiety will be useful for targeting the drug to macrophage and dendritic cells, which are primary targets for HIV-1 infection and are expressing mannose- and oligomanose-specific receptors on their surface. In combination with site-specific mutagenesis, the maleimide-activated carbohydrates can serve as generally applicable tags for site-specific glycosylation of proteins via the highly efficient maleimide-thiol ligation reaction.
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Affiliation(s)
- Jiahong Ni
- Institute of Human Virology, University of Maryland Biotechnology Institute, University of Maryland, 725 W. Lombard Street, Baltimore, Maryland 21201, USA
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385
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Filira F, Biondi B, Biondi L, Giannini E, Gobbo M, Negri L, Rocchi R. Opioid peptides: synthesis and biological properties of [(Nγ-glucosyl,Nγ-methoxy)-α,γ-diamino-(S)-butanoyl]4-deltorphin-1-neoglycopeptide and related analogues. Org Biomol Chem 2003; 1:3059-63. [PMID: 14518129 DOI: 10.1039/b306142f] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The [D-Ala2]deltorphin 1 sequence in which the aspartic acid residue is replaced by the N gamma-OCH3-alpha, gamma-diamino (S) butanoyl residue was synthesized using the Fmoc-chemistry-based solid phase procedure. The resulting deltorphin analogue was chemoselectively glucosylated by reaction with unprotected D-glucose (Glc). The Asn4-, (2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-beta-D-galactopyranosyl)-Asn4- and the (2-acetamido-2-deoxy-D-galactopyranosyl)-Asn4-deltorphin I were also prepared for comparison. The affinity of the new compounds for the delta-opioid receptor was expressed by the inhibition constant (Ki) of the binding of the delta-receptor selective ligand [3H]naltrindole (NTI) to rat brain membrane preparations. The in vitro biological activity of the synthetic peptides was compared with that of the mu-opioid receptor agonist dermorphin in guinea pig ileum (GPI) preparations and with that of the delta-opioid receptor agonist deltorphin I in mouse vas deferens (MVD) preparations. The substitution of Asp4 with Asn failed to affect drastically the Ki and IC50 values for delta-sites, suggesting that an electrostatic interaction does not play an essential role in the binding to delta-opioid sites. The steric hindrance of the side chain of the residue in position 4 affects binding to delta-sites. The increase of the Ki value is smaller when the sugar-peptide linkage involves the gamma-nitrogen of the Dab residue in comparison with the Asn amide side chain.
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Affiliation(s)
- Fernando Filira
- Department of Organic Chemistry, University of Padova, Institute of Biomolecular Chemistry, C. N. R., Section of Padova, via Marzolo, 1-35131, Padova, Italy
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386
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387
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De Vos DE, Dams M, Sels BF, Jacobs PA. Ordered mesoporous and microporous molecular sieves functionalized with transition metal complexes as catalysts for selective organic transformations. Chem Rev 2002; 102:3615-40. [PMID: 12371896 DOI: 10.1021/cr010368u] [Citation(s) in RCA: 939] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dirk E De Vos
- Center for Surface Chemistry & Catalysis, K. U. Leuven, Kasteelpark Arenberg 23, 3001 Heverlee, Belgium
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388
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Iserloh U, Dudkin V, Wang ZG, Danishefsky SJ. Reducing oligosaccharides via glycal assembly: on the remarkable stability of anomeric hydroxyl groups to global deprotection with sodium in liquid ammonia. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)01551-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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389
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Preparation of glycosyl amino acids as building blocks for the combinatorial synthesis of neoglycoconjugates. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0957-4166(02)00212-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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