Notes

Capsule Covering Bacteria Host Defenses
The assembly and translocation of the capsule requires proteins in the inner and outer membranes. The inner membrane protein Wzc is a tyrosine autokinase that plays an essential role in what is believed to be a coordinated biosynthesis and secretion process. Mutants lacking Wzc can form K antigen oligosaccharides but are unable to polymerize high molecular weight capsular polymers. Wzc homologs have been identified in exopolymer biosynthesis systems in many different Gram-negative and -positive bacteria. Using single particle averaging on cryo-negatively stained samples, we have produced the first three-dimensional structure of this type of membrane protein in its phosphorylated state at approximately 14 A resolution. Perfluoro-octanoate-PAGE analysis of detergent-solubilized oligomeric Wzc and symmetry analysis of the transmission electron microscopy data clearly demonstrated that Wzc forms a tetrameric complex with C4 rotational symmetry.

Viewed from Seebio 2'-FL of the complex, the oligomer is square with a diameter of approximately 0 A and can be divided into four separate densities. From the side, Wzc is approximately 1 A high and has a distinctive appearance similar to an extracted molar tooth. The upper crown region is approximately 55 A high and forms a continuous ring of density. Four unconnected roots ( approximately 65 A high) emerge from the underside of the crown. We propose that the crown is formed by protein-protein contacts from the four Wzc periplasmic domains, while each root represents an individual cytoplasmic tyrosine autokinase domain.Sequence analysis of highly sulfated, heparin-derived oligosaccharides using fast atom bombardment mass spectrometry.Heparin, a polydisperse, sulfated copolymer of 1----4 linked glucosamine and uronic acid residues, has been used clinically as an anticoagulant for half a century.

Despite a yearly use of over million doses in the U.S. alone, heparin's exact chemical structure remains unclear. The negative ion fast atom bombardment mass spectrometry (FAB-MS) analysis is presented for a series of enzymatically prepared, homogeneous, structurally characterized, highly sulfated, heparin-derived oligosaccharides using triethanolamine as the FAB matrix. In addition to the clear presence of monoanionic sodiated molecular ions, structurally significant (sequence) fragment ions are observed and characterized with respect to the known structure for five of the heparin-derived oligosaccharides. The structure of a sixth oligosaccharide is predicted by using negative ion FAB-MS and subsequently confirmed by chemical, enzymatic, and NMR spectroscopic methods.Interfering with the sugar code design and synthesis of oligosaccharide mimics.

Oligosaccharide determinants of cellular glycoconjugates interact with protein receptors triggering a variety of cellular responses within a wide range of physiological and pathological processes and with exquisitely tuned selectivity. This has led to the formulation of the hypothesis that a sugar code exists and that sugar-binding proteins (lectins) act to decipher it and translate it into biological responses. Oligosaccharides with these recognition events by functional mimics of carbohydrates could thus be used to modulate or alter signal transmission, or to prevent the onset of diseases. Attempts to design and prepare glycomimetic inhibitors of well-known target lectins (cholera toxin, DC-SIGN) are reviewed in this concept paper.Application of electrospray ionization with Fourier transform ion cyclotron resonance mass spectrometry for structural screening of core oligosaccharides from lipopolysaccharides of the bacteria Proteus.Electrospray ionization with Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICRMS) was used for screening and structural elucidation of core oligosaccharides isolated from lipopolysaccharides of bacteria of the genus Proteus. Mass spectra allowed the determination of the molecular masses with high accuracy and the estimation of the chemical heterogeneity of the samples.

They did not, however, provide sufficient information to identify structural details of the branched oligosaccharides. Therefore, various fragmentation techniques for determining such details were examined. Infrared multiphoton dissociation tandem mass spectrometry (IRMPD-MSMS) experiments in negative ion mode resulted in cleavage between the structurally conserved inner core region and the variable outer core region. Positive ion capillary skimmer dissociation mass spectra showed numerous fragment ion peaks, including those corresponding to the subsequent cleavage of the glycosidic linkages starting from the non-reducing end of the oligosaccharide.
Here's my website: https://en.wikipedia.org/wiki/2%27-Fucosyllactose