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  • 1.
    Fontana, Carolina
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Zaccheus, Mona V.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Weintraub, Andrej
    Ansaruzzaman, Mohammad
    Widmalm, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Structural studies of a polysaccharide from Vibrio parahaemolyticus strain AN-160002016Ingår i: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 432, s. 41-49Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The structure of a polysaccharide from Vibrio parahaemolyticus strain AN-16000 has been investigated. The sugar and absolute configuration analysis revealed D-Glc, D-GalN, D-QuiN and L-FucN as major components. The PS was subjected to dephosphorylation with aqueous 40% HF to obtain an oligosaccharide that was analyzed by H-1 and C-13 NMR spectroscopy. The HR-MS spectrum of the oligosaccharide revealed a pentasaccharide composed of two Glc residues, one QuiNAc and one GalNAc, one FucNAc, as well as a glycerol moiety. The structure of the PS was determined using H-1, C-13, N-15 and P-31 NMR spectroscopy; inter-residue correlations were identified by H-1, C-13-heteronuclear multiple-bond correlation, H-1, H-1-NOESY and H-1, P-31-hetero-TOCSY experiments. The PS backbone has the following teichoic acid-like structure: -> 3)-D-Gro-(1-P-6)-beta-D-Glcp-(1 -> 4)-alpha-L-FucpNAc-(1 -> 3)-beta-D-QuipNAc-(1 -> with a side-chain consisting of alpha-D-Glcp-(1 -> 6)-alpha-D-GalpNAc-(1 -> linked to the O3 position of the FucNAc residue.

  • 2. Godefroid, Marie
    et al.
    Svensson, Mona V
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Cambier, Pierre
    Uzureau, Sophie
    Mirabella, Aurélie
    De Bolle, Xavier
    Van Cutsem, Pierre
    Widmalm, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Letesson, Jean-Jacques
    Brucella melitensis 16M produces a mannan and other extracellular matrix components typical of a biofilm2010Ingår i: FEMS Immunology and Medical Microbiology, ISSN 0928-8244, E-ISSN 1574-695X, Vol. 59, nr 3, s. 364-377Artikel i tidskrift (Refereegranskat)
  • 3. Hugerth, A
    et al.
    Brisander, M
    Wrange, U
    Kritikos, M
    Stockholms universitet.
    Norrlind, B
    Svensson, M
    Stockholms universitet.
    Bisrat, M
    Ostelius, J
    Physical characterization of anyhydrous and hydrous forms of the hydrochloride salt of BVT.5182 a novel 5-HT6 receptor antagonist2006Ingår i: Drug Development and Industrial Pharmacy, Vol. 32, s. 185-196Artikel i tidskrift (Refereegranskat)
  • 4. Hughert, A
    et al.
    Brisander, M
    Wrange, U
    Kritikos, M
    Stockholms universitet.
    Norrlind, B
    Svensson, M
    Stockholms universitet.
    Bisrat, M
    Ostelius, J
    Physical characterization of anhydrous and hydrous forms of the hydrochloride salt of BVT.5182 a novel 5-HT6 receptor antagonist2006Ingår i: Drug Development and Industrial Pharmacy, Vol. 32, s. 185-196Artikel i tidskrift (Refereegranskat)
  • 5. Liu, Bin
    et al.
    Perepelov, Andrei V.
    Svensson, Mona V.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Shevelev, Sergei D.
    Guo, Dan
    Senchenkova, Sof'ya N.
    Shashkov, Alexander S.
    Weintraub, Andrej
    Feng, Lu
    Widmalm, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Knirel, Yuriy A.
    Wang, Lei
    Genetic and structural relationships of Salmonella O55 and Escherichia coli O103 O-antigens and identification of a 3-hydroxybutanoyltransferase gene involved in the synthesis of a Fuc3N derivative2010Ingår i: Glycobiology, ISSN 0959-6658, E-ISSN 1460-2423, Vol. 20, nr 6, s. 679-688Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    O-antigen (O-polysaccharide), a part of the outer membrane of Gram-negative bacteria, is one of the most variable cell constituents and is related to bacterial virulence. O-antigen diversity is almost entirely due to genetic variations in O-antigen gene clusters. In this study, the O-polysaccharide structures of Salmonella O55 and Escherichia coli O103 were elucidated by chemical analysis and nuclear magnetic resonance spectroscopy. It was found that the O-polysaccharides have similar pentasaccharide O-units, which differ only in one sugar (glucose versus N-acetylglucosamine) and in the N-acyl group (acetyl versus 3-hydroxybutanoyl) on 3-amino-3,6-dideoxy-d-galactose (d-Fuc3N). The Salmonella O55 antigen gene cluster was sequenced and compared with the E. coli O103 antigen gene cluster reported previously. The two gene clusters were found to share high-level similarity (DNA identity ranges from 53% to 76%), except for two putative acyl transferase genes (fdtC in Salmonella O55 and fdhC in E. coli O103) which show no similarity. Replacement of the fdtC gene in Salmonella O55 with the fdhC gene from E. coli O103 resulted in production of a modified O-antigen, which contains a 3-hydroxybutanoyl derivative of Fuc3N in place of 3-acetamido-3,6-dideoxygalactose. This finding strongly suggests that fdhC is a 3-hydroxybutanoyltransferase gene. The sequence similarity level suggested that the O-antigen gene clusters of Salmonella O55 and E. coli O103 originate from a common ancestor, and this evolutionary relationship is discussed.

  • 6. Martínez-Gómez, Estrella
    et al.
    Ståhle, Jonas
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Gil-Ramírez, Yolanda
    Zúñiga-Ripa, Amaia
    Zaccheus, Mona
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Moriyón, Ignacio
    Iriarte, Maite
    Widmalm, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Conde-Álvarez, Raquel
    Genomic Insertion of a Heterologous Acetyltransferase Generates a New Lipopolysaccharide Antigenic Structure in Brucella abortus and Brucella melitensis2018Ingår i: Frontiers in Microbiology, ISSN 1664-302X, E-ISSN 1664-302X, Vol. 9, artikel-id 1092Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Brucellosis is a bacterial zoonosis of worldwide distribution caused by bacteria of the genus Brucella. In Brucella abortus and Brucella melitensis, the major species infecting domestic ruminants, the smooth lipopolysaccharide (S-LPS) is a virulence factor. This S-LPS carries a N-formyl-perosamine homopolymer O-polysaccharide that is the major antigen in serodiagnostic tests and is required for virulence. We report that the Brucella O-PS can be structurally and antigenically modified using wbdR, the acetyl-transferase gene involved in N-acetyl-perosamine synthesis in Escherichia coli O157:H7. Brucella constructs carrying plasmidic wbdR expressed a modified O-polysaccharide but were unstable, a problem circumvented by inserting wbdR into a neutral site of chromosome II. As compared to wild-type bacteria, both kinds of wbdR constructs expressed shorter O-polysaccharides and NMR analyses showed that they contained both N-formyl and N-acetyl-perosamine. Moreover, deletion of the Brucella formyltransferase gene wbkC in wbdR constructs generated bacteria producing only N-acetyl-perosamine homopolymers, proving that wbdR can replace for wbkC. Absorption experiments with immune sera revealed that the wbdR constructs triggered antibodies to new immunogenic epitope(s) and the use of monoclonal antibodies proved that B. abortus and B. melitensis wbdR constructs respectively lacked the A or M epitopes, and the absence of the C epitope in both backgrounds. The wbdR constructs showed resistance to polycations similar to that of the wild-type strains but displayed increased sensitivity to normal serum similar to that of a per R mutant. In mice, the wbdR constructs produced chronic infections and triggered antibody responses that can be differentiated from those evoked by the wild-type strain in S-LPS ELISAs. These results open the possibilities of developing brucellosis vaccines that are both antigenically tagged and lack the diagnostic epitopes of virulent field strains, thereby solving the diagnostic interference created by current vaccines against Brucella.

  • 7.
    Roslund, Mattias U.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Säwén, Elin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Landström, Jens
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Rönnols, Jerk
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Jonsson, K. Hanna M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Lundborg, Magnus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Svensson, Mona V.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Widmalm, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Complete 1H and 13C NMR chemical shift assignments of mono-, di-, and trisaccharides as basis for NMR chemical shift predictions of polysaccharides using the computer program CASPER2011Ingår i: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 346, nr 11, s. 1311-1319Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The computer program casper uses 1H and 13C NMR chemical shift data of mono- to trisaccharides for the prediction of chemical shifts of oligo- and polysaccharides. In order to improve the quality of these predictions the 1H and 13C, as well as 31P when applicable, NMR chemical shifts of 30 mono-, di-, and trisaccharides were assigned. The reducing sugars gave two distinct sets of NMR resonances due to the α- and β-anomeric forms. In total 35 1H and 13C NMR chemical shift data sets were obtained from the oligosaccharides. One- and two-dimensional NMR experiments were used for the chemical shift assignments and special techniques were employed in some cases such as 2D 1H,13C-HSQC Hadamard Transform methodology which was acquired approximately 45 times faster than a regular t1 incremented 1H,13C-HSQC experiment and a 1D 1H,1H-CSSF-TOCSY experiment which was able to distinguish spin-systems in which the target protons were only 3.3 Hz apart. The 1H NMR chemical shifts were subsequently refined using total line-shape analysis with the PERCH NMR software. The acquired NMR data were then utilized in the casper program (http://www.casper.organ.su.se/casper/) for NMR chemical shift predictions of the O-antigen polysaccharides from Klebsiella O5, Shigella flexneri serotype X, and Salmonella arizonae O62. The data were compared to experimental data of the polysaccharides from the two former strains and the lipopolysaccharide of the latter strain showing excellent agreement between predicted and experimental 1H and 13C NMR chemical shifts.

  • 8.
    Rönnols, Jerk
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Pendrill, Robert
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Fontana, Carolina
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Hamark, Christoffer
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Angles d'Ortoli, Thibault
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Engström, Olof
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Ståhle, Jonas
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Zaccheus, Mona V.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Säwén, Elin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Hahn, Liljan E.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Iqbal, Shahzad
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Widmalm, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Complete H-1 and C-13 NMR chemical shift assignments of mono- to tetrasaccharides as basis for NMR chemical shift predictions of oligosaccharides using the computer program CASPER2013Ingår i: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 380, s. 156-166Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    H-1 and C-13 NMR chemical shift data are used by the computer program CASPER to predict chemical shifts of oligo- and polysaccharides. Three types of data are used, namely, those from monosaccharides, disaccharides, and trisaccharides. To improve the accuracy of these predictions we have assigned the H-1 and C-13 NMR chemical shifts of eleven monosaccharides, eleven disaccharides, twenty trisaccharides, and one tetrasaccharide; in total 43 compounds. Five of the oligosaccharides gave two distinct sets of NMR resonances due to the alpha- and beta-anomeric forms resulting in 48 H-1 and C-13 NMR chemical shift data sets. In addition, the pyranose ring forms of Neu5Ac were assigned at two temperatures, due to chemical shift displacements as a function of temperature. The H-1 NMR chemical shifts were refined using total line-shape analysis with the PERCH NMR software. H-1 and C-13 NMR chemical shift predictions were subsequently carried out by the CASPER program (http://www.casper.organ.su.se/casper/) for three branched oligosaccharides having different functional groups at their reducing ends, namely, a mannose-containing pentasaccharide, and two fucose-containing heptasaccharides having N-acetyllactosamine residues in the backbone of their structures. Good to excellent agreement was observed between predicted and experimental H-1 and C-13 NMR chemical shifts showing the utility of the method for structural determination or confirmation of synthesized oligosaccharides.

  • 9.
    Svensson, Mona
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Solution structure of a central fragment of tumor antigen LeaLex2009Ingår i: Abstracts of Papers, 238th ACS National Meeting, Washington, DC, United States, August 16-20, 2009, American Chemical Society , 2009Konferensbidrag (Övrigt vetenskapligt)
  • 10.
    Svensson, Mona
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Structure elucidation of O-antigen polysaccharides from Escherichia coli2010Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 11.
    Svensson, Mona V.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Weintraub, Andrej
    Widmalm, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Structural elucidation of the O-antigenic polysaccharide from Escherichia coli O1752011Ingår i: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 346, nr 3, s. 449-453Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The structure of the O-antigen polysaccharide (PS) from Escherichia coli O175 has been elucidated. Component analysis together with 1H and 13C NMR spectroscopy experiments were used to determine the structure. Inter-residue correlations were determined by 1H,1H-NOESY, and 1H,13C-heteronuclear multiple-bond correlation experiments. The PS is composed of pentasaccharide repeating units with the following structure:

    →2)-α-d-Glcp-(1→4)-α-d-GlcpA-(1→3)-α-d-Manp-(1→2)-α-d-Manp-(1→3)-β-d-GalpNAc-(1→

    Cross-peaks of low intensity from an α-linked glucopyranosyl residue were present in the 1H,1H-TOCSY NMR spectra. The α-d-Glcp residue is suggested to originate from the terminal part of the polysaccharide and consequently the biological repeating unit has a 3-substituted N-acetyl-d-galactosamine residue at its reducing end. The repeating unit of the E. coli O175 O-antigen is similar to those from E. coli O22 and O83, both of which carry an α-d-Glcp-(1→4)-d-GlcpA structural element, thereby explaining the reported cross-reactivities between the strains.

  • 12.
    Svensson, Mona V.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Weintraub, Andrej
    Widmalm, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Structural studies of the O-antigenic polysaccharide from Escherichia coli O1772011Ingår i: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 346, nr 14, s. 2300-2303Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The structure of the O-antigen polysaccharide (PS) from Escherichia coli O177 has been determined. Component analysis together with 1H and 13C NMR spectroscopy experiments was used to determine the structure. Inter-residue correlations were determined by 1H,13C-heteronuclear multiple-bond correlation and 1H,1H-NOESY experiments. PS is composed of tetrasaccharide repeating units with the following structure:

    →2)-α-l-Rhap-(1→3)-α-l-FucpNAc-(1→3)-α-l-FucpNAc-(1→3)-β-d-GlcpNAc-(1→

    An α-l-Rhap residue is suggested to be present at the terminal part of the polysaccharide, which on average is composed of ∼20 repeating units, since the 1H and 13C chemical shifts of an α-linked rhamnopyranosyl group could be assigned by a combination of 2D NMR spectra. Consequently, the biological repeating unit has a 3-substituted N-acetyl-d-glucosamine residue at its reducing end. The repeating unit of the E. coli O177 O-antigen shares the →3)-α-l-FucpNAc-(1→3)-β-d-GlcpNAc-(1→ structural element with the O-antigen from E. coli O15 and this identity may then explain the reported cross-reactivity between the strains.

  • 13.
    Svensson, Mona V.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Zhang, Xue
    Huttunen, Eine
    Widmalm, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Structural studies of the capsular polysaccharide produced by Leuconostoc mesenteroides ssp. cremoris PIA22011Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 12, nr 7, s. 2496-2501Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The structure of the capsular polysaccharide (CPS) produced by Leuconostoc mesenteroides ssp. cremoris PIA2 has been determined using component analysis and NMR spectroscopy. 1H and 13C resonances were assigned using 2D NMR experiments, and sequential information was obtained by 1H,1H-NOESY and 1H,13C-HMBC experiments. The CPS consists of linear pentasaccharide repeating units with the following structure: →3)-β-d-Galf-(1→6)-β-d-Galf-(1→2)-β-d-Galf-(1→6)-β-d-Galf-(1→3)-β-d-Galp-(1→, in which four out of the five sugar residues have the furanoid ring form, a structural entity found in bacteria but not in mammals. The analysis of the magnitude of the homonuclear three-bond coupling constants of the anomeric protons for the five-membered sugar rings indicates that the sugar residues substituted at a primary carbon atom show one kind of conformational preferences, whereas those substituted at a secondary carbon atom show another kind of conformational preferences.

  • 14.
    Zaccheus, Mona
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Structural and Conformational Studies of Oligo- and Polysaccharides2012Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The focus of this thesis is to examine the structural properties of polysaccharides produced by bacteria, as well as the dynamic and conformational behavior of a synthetically derived oligosaccharide.

    The primary structures of the O-polysaccharide repeating units of four different Escherichia coli (E. coli) strains, namely O175, O177, O103 and TD2158, as well as the first report of a capsular polysaccharide produced by lactic acid bacteria Leuconostoc mesenteroides ssp. cremoris PIA2 are reported in paper I–V. Structural analyses have been performed using a combination of nuclear magnetic resonance spectroscopy and chemical component analysis.

    The elucidated structures in paper I–III, as well as paper V, are composed of linear repeating units of varying composition and length. In paper IV, the structure of the O-polysaccharide repeating unit of E. coli TD2158 is determined to be a branched hexasaccharide structure with a heterogeneous substitution pattern, with either a β-GlcpNAc or β-Glcp residue branching to the backbone chain. Incubation with bacteriophage HK620 tailspike protein shows that the polysaccharide is selectively cleaved at the α-GlcpNAc-(1→2)-α-Rhap-linkage of the backbone chain, yielding a 9:1 ratio of β-GlcpNAc/β-Glcp containing hexasaccharides after digestion.

    In paper VI the conformational properties of a trisaccharide, which constitutes an internal epitope of the LeaLex hexasaccharide over-expressed on the surface of squamous lung cancer cells, have been analyzed using NMR spectroscopy and molecular dynamics simulations. The β-(1→3)-linkage of the trisaccharide was shown to be highly flexible.

  • 15.
    Zaccheus, Mona V.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Broeker, Nina K.
    Lundborg, Magnus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Uetrecht, Charlotte
    Barbirz, Stefanie
    Widmalm, Göran
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för organisk kemi.
    Structural studies of the O‐antigen polysaccharide from Escherichia coli TD2158 having O18 serogroup specificity and aspects of its interaction with the tailspike endoglycosidase of the infecting bacteriophage HK6202012Ingår i: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 357, s. 118-125Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have analyzed the O-antigen polysaccharide of the previously uncharacterized Escherichia coli strain TD2158 which is a host of bacteriophage HK620. This bacteriophage recognizes and cleaves the polysaccharide with its tailspike protein (TSP). The polysaccharide preparation as well as oligosaccharides obtained from HK620TSP endoglycosidase digests were analyzed with NMR spectroscopy. Additionally, sugar analysis was performed on the O-antigen polysaccharide and MALDI-TOF MS was used in oligosaccharide analysis. The present study revealed a heterogeneous polysaccharide with a hexasaccharide repeating unit of the following structure: α-D-Glcp-(1→6|) →2)-α-L-Rhap-91→6)-α-D-Glcp-(1→4)-α-D-Ga|lp-(1→3)-α-D-GlcpNAc-(1→ β-D-Glcp/β-D-GlcpNAc-(1→3) A repeating unit with a D-GlcNAc substitution of D-Gal has been described earlier as characteristic for serogroup O18A1. Accordingly, we termed repeating units with D-Glc substitution at D-Gal as O18A2. NMR analyses of the polysaccharide confirmed that O18A1- and O18A2-type repeats were present in a 1:1 ratio. However, HK620TSP preferentially bound the D-GlcNAc-substituted O18A1-type repeating units in its high affinity binding pocket with a dissociation constant of 140 μM and disfavored the O18A2-type having a β-D-Glcp-(1→3)-linked group. As a result, in hexasaccharide preparations, O18A1 and O18A2 repeats were present in a 9:1 ratio stressing the clear preference of O18A1-type repeats to be cleaved by HK620TSP.

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