Structural characterization of the antigenic capsular polysaccharide and lipopolysaccharide O-chain produced byActinobacillus pleuropneumoniaeserotype 15

2005 ◽  
Vol 83 (1) ◽  
pp. 61-69 ◽  
Author(s):  
Malcolm B Perry ◽  
Leann L MacLean ◽  
Evgeny Vinogradov
Keyword(s):  
Molecular Mass ◽  
Key Words ◽  
Structural Characterization ◽  
Capsular Polysaccharide ◽  
Actinobacillus Pleuropneumoniae ◽  
High Molecular Mass ◽  
O Antigen ◽  
Phosphate Diester ◽  
Nmr Methods

The specific capsular polysaccharide produced by Actinobacillus pleuropneumoniae serotype 15 was determined to be a high-molecular-mass polymer having [α]D+ 69° (water) and composed of a linear backbone of phosphate diester linked disaccharide units of 2-acetamido-2-deoxy-D-glucose (D-GlcNAc) and 2-acetamido-2-deoxy-D-galactose (D-GalNAc) residues (1:1). Thirty percent of the D-GalNAc residues were substituted at O-4 by β-D-galactopyranose (β-D-Galp) residues. Through the application of chemical and NMR methods, the capsule, which defines the serotype specificity of the bacterium, was found to have the structure                        [Formula: see text]The O-polysaccharide (O-PS) component of the A. pleuro pneumoniae serotype 15 lipopolysaccharide (LPS) was characterized as a linear unbranched polymer of repeating pentasaccharide units composed of D-glucose (2 parts) and D-galactose (3 parts), shown to have the structure[Formula: see text]The O-PS was chemically identical with the O-antigen previously identified in the LPSs produced by A. pleuro pneumoniae serotypes 3 and 8. Key words: Capsule, lipopolysaccharide, Actinobacillus pleuropneumoniae serotype 15.

scholarly journals Structural characterization of the lipopolysaccharide O-antigen and capsular polysaccharide of Vibrio ordalii serotype O : 2

1998 ◽  
Vol 253 (1) ◽  
pp. 319-327 ◽  
Author(s):  
Irina Sadovskaya ◽  
Jean-Robert Brisson ◽  
Nam Huan Khieu ◽  
Lucy M. Mutharia ◽  
Eleonora Altman
Keyword(s):  
Structural Characterization ◽  
Capsular Polysaccharide ◽  
O Antigen ◽  
Serotype O ◽  
Vibrio Ordalii

scholarly journals Solid-State NMR Techniques for the Structural Characterization of Cyclic Aggregates Based on Borane–Phosphane Frustrated Lewis Pairs

Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1400 ◽  
Author(s):  
Robert Knitsch ◽  
Melanie Brinkkötter ◽  
Thomas Wiegand ◽  
Gerald Kehr ◽  
Gerhard Erker ◽  
...  
Keyword(s):  
Solid State ◽  
Structural Characterization ◽  
Solid State Nmr ◽  
Magic Angle ◽  
Frustrated Lewis Pairs ◽  
Wide Range ◽  
Nmr Techniques ◽  
Nmr Methods ◽  
Lewis Pairs

Modern solid-state NMR techniques offer a wide range of opportunities for the structural characterization of frustrated Lewis pairs (FLPs), their aggregates, and the products of cooperative addition reactions at their two Lewis centers. This information is extremely valuable for materials that elude structural characterization by X-ray diffraction because of their nanocrystalline or amorphous character, (pseudo-)polymorphism, or other types of disordering phenomena inherent in the solid state. Aside from simple chemical shift measurements using single-pulse or cross-polarization/magic-angle spinning NMR detection techniques, the availability of advanced multidimensional and double-resonance NMR methods greatly deepened the informational content of these experiments. In particular, methods quantifying the magnetic dipole–dipole interaction strengths and indirect spin–spin interactions prove useful for the measurement of intermolecular association, connectivity, assessment of FLP–ligand distributions, and the stereochemistry of adducts. The present review illustrates several important solid-state NMR methods with some insightful applications to open questions in FLP chemistry, with a particular focus on supramolecular associates.

scholarly journals Characterization of derivatives of the high-molecular-mass penicillin-binding protein (PBP) 1 of Mycobacterium leprae

2000 ◽  
Vol 350 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Sebabrata MAHAPATRA ◽  
Sanjib BHAKTA ◽  
Jasimuddin AHAMED ◽  
Joyoti BASU
Keyword(s):  
Plasma Membrane ◽  
Molecular Mass ◽  
Mycobacterium Leprae ◽  
Binding Activity ◽  
High Molecular Mass ◽  
Class A ◽  
C Terminus ◽  
Fusion Junction ◽  
Derivatives Of

Mycobacterium leprae has two high-molecular-mass multimodular penicillin-binding proteins (PBPs) of class A, termed PBP1 and PBP1* [Lepage, Dubois, Ghosh, Joris, Mahapatra, Kundu, Basu, Chakrabarti, Cole, Nguyen-Disteche and Ghuysen (1997) J. Bacteriol. 179, 4627–4630]. PBP1-Xaa–β-lactamase fusions generated periplasmic β-lactamase activity when Xaa (the amino acid of PBP1 at the fusion junction) was residue 314, 363, 407, 450 or 480. Truncation of the N-terminal part of the protein up to residue Leu-147 generated a penicillin-binding polypeptide which could still associate with the plasma membrane, whereas [∆M1–R314]PBP1 (PBP1 lacking residues Met-1 to Arg-314) failed to associate with the membrane, suggesting that the region between residues Leu-147 and Arg-314 harbours an additional plasma membrane association site for PBP1. Truncation of the C-terminus up to 42 residues downstream of the KTG (Lys-Thr-Gly) motif also generated a polypeptide that retained penicillin-binding activity. [∆M1–R314]PBP1 could be extracted from inclusion bodies and refolded under appropriate conditions to give a form capable of binding penicillin with the same efficiency as full-length PBP1. This is, to the best of our knowledge, the first report of a soluble derivative of a penicillin-resistant high-molecular-mass PBP of class A that is capable of binding penicillin. A chimaeric PBP in which the penicillin-binding (PB) module of PBP1 was fused at its N-terminal end with the non-penicillin-binding (n-PB) module of PBP1* retained pencillin-binding activity similar to that of PBP1, corroborating the finding that the n-PB module of PBP1 is dispensable for its penicillin-binding activity.

scholarly journals Immunochemical characterization of mucins. Polypeptide (M1) and polysaccharide (A and Leb) antigens

1988 ◽  
Vol 254 (1) ◽  
pp. 185-193 ◽  
Author(s):  
J Bara ◽  
R Gautier ◽  
J Le Pendu ◽  
R Oriol
Keyword(s):  
Monoclonal Antibodies ◽  
Molecular Mass ◽  
High Molecular Mass ◽  
Density Gradient Ultracentrifugation ◽  
Blood Group Antigens ◽  
Lewis Blood Group ◽  
Progressive Loss ◽  
Cscl Density Gradient ◽  
Mucinous Cyst

Seven monoclonal antibodies (MAbs) reacting with high-molecular-mass components (greater than 20,000 kDa) isolated from an ovarian mucinous cyst of an A Le(a-b+) patient are described. By the use of immunoradiometric methods, these MAbs characterized seven different epitopes associated with components having a density of 1.45 g/ml by CsCl-density-gradient ultracentrifugation, like mucins. Two MAbs reacted with A and Lewis blood-group antigens respectively (polysaccharide epitopes). The five other MAbs characterized five M1 epitopes (called a, b, c, d and e), mainly associated with components of more than 20,000 kDa and 2000 kDa. They were completely destroyed by papain and 2-mercaptoethanol treatment (polypeptide epitopes). Moreover, timed trypsin digestion of native mucin resulted in a progressive loss of M1 activity and degraded these mucins into smaller M1-positive fragments. The a and c epitopes were partially degraded from relatively high-molecular-mass fragments (2000 kDa to 500 kDa) into a 100 kDa fragment. The b and d epitopes were completely degraded into smaller fragments ranging from 100 kDa to 40 kDa. The e epitope was completely destroyed by trypsin. These different pathways of M1 antigen degradation suggest the occurrence of different epitopes located in separate regions of the mucin molecules.

Sign in / Sign up

Export Citation Format

Share Document