Fusarium and Giberella species were found to secrete acidic polysaccharides when grown in Czapex-Dox medium. Fusarium oxysporum showed the highest rate of secretion of acidic sugars into the growth medium. The acidic sugar-containing glycoprotein from F. oxysporum was purified from the culture filtrate to apparent homogeneity on ultracentrifugation analysis, by ammonium sulfate precipitation, Toyopearl HW-55 gel filtration and charcoal chromatography. The purified acidic sugar-containing glycoprotein has a 10% protein content and a content of 40% acidic sugars as glucuronic acid, and the neutral sugars present in this glycoprotein are mainly mannose, galactose, and glucose. The protein moiety of the glycoprotein contains a high proportion of serine and threonine residues. Treatment of the glycoprotein with alkaline solution resulted in an increase in absorbance at 241 nm, and alkaline borohydride treatment resulted in a marked decrease in the number of serine and threonine residues. We conclude that the glycoprotein has O-linked sugar chains which are mainly attached to serine and threonine residues of the protein moiety. The primary structure of the acidic polysaccharide from F. oxysporum was analyzed mainly by NMR spectrometry. The main parts of this polysaccharide have structures similar to those of uronic acid-containing polysaccharide from Fusarium sp. M7-1.

acidic polysaccharide, glucuronic acid, glycoprotein, Fusarium

13C NMR data:
missing...

There are 6 chemically distinct structures. Please, select:
-6)[aDGlcp(1-2)]bDGalf(1-6)[Subst(1-2)]bDGalf(1-6)[bDManp(1-4)aDGlcpA(1-2)]bDGalf(1-6)[bDManp(1-2)bDManp(1-4)aDGlcpA(1-2)]bDGalf(1- // Subst = unidentified oligosaccharide -6)[aDGlcp(1-2)]bDGalf(1-6)[Subst(1-3)]bDGalf(1-6)[bDManp(1-4)aDGlcpA(1-2)]bDGalf(1-6)[bDManp(1-2)bDManp(1-4)aDGlcpA(1-2)]bDGalf(1- // Subst = unidentified oligosaccharide -6)[aDGlcp(1-2)]bDGalf(1-6)[Subst(1-5)]bDGalf(1-6)[bDManp(1-4)aDGlcpA(1-2)]bDGalf(1-6)[bDManp(1-2)bDManp(1-4)aDGlcpA(1-2)]bDGalf(1- // Subst = unidentified oligosaccharide -6)[aDGlcf(1-2)]bDGalf(1-6)[Subst(1-2)]bDGalf(1-6)[bDManp(1-4)aDGlcpA(1-2)]bDGalf(1-6)[bDManp(1-2)bDManp(1-4)aDGlcpA(1-2)]bDGalf(1- // Subst = unidentified oligosaccharide -6)[aDGlcf(1-2)]bDGalf(1-6)[Subst(1-3)]bDGalf(1-6)[bDManp(1-4)aDGlcpA(1-2)]bDGalf(1-6)[bDManp(1-2)bDManp(1-4)aDGlcpA(1-2)]bDGalf(1- // Subst = unidentified oligosaccharide -6)[aDGlcf(1-2)]bDGalf(1-6)[Subst(1-5)]bDGalf(1-6)[bDManp(1-4)aDGlcpA(1-2)]bDGalf(1-6)[bDManp(1-2)bDManp(1-4)aDGlcpA(1-2)]bDGalf(1- // Subst = unidentified oligosaccharide

SVGMWSMILES3D molIonize

 

R1 = unidentified oligosaccharide
*OC[C@@H](O)[C@@H]1O[C@@H](OC[C@@H](O)[C@@H]2O[C@@H](OC[C@@H](O)[C@@H]3O[C@@H](OC[C@@H](O)[C@@H]4O[C@@H](*)[C@H](O[C@H]5O[C@H](C(=O)O)[C@@H](O[C@@H]6O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]6O[C@@H]6O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]6O)[C@H](O)[C@H]5O)[C@H]4O)[C@H](O[C@H]4O[C@H](C(=O)O)[C@@H](O[C@@H]5O[C@H](CO)[C@@H](O)[C@H](O)[C@@H]5O)[C@H](O)[C@H]4O)[C@H]3O)[C@H](O[1*])[C@H]2O)[C@H](O[C@H]2O[C@H](CO)[C@@H](O)[C@H](O)[C@H]2O)[C@H]1O

1648.368 g/mol (C₆₀H₉₅R₃O₅₂, R = next and previous repeats / underdetermined substituent(s), not counted in mol weight)

Infection of Aerobacter aerogenes with a phage isolated from raw sewage induces the de novo synthesis of a polysaccharide depolymerase active against the capsular polysaccharide of the host organism. The enzyme exists in two forms, soluble and phage-bound. The soluble form has been purified to apparent homogeneity, as judged by disc gel electrophoresis and molecular sieve chromatography, and possesses the following molecular properties: (a) sedimentation coefficient, 10.7 S; (b) Stokes radius, 86.2 Å; (c) molecular weight, 379,000; and (d) frictional ratio, 1.77. Treatment of depolymerase with sodium dodecyl sulfate at 42-62° results in dissociation to two apparently nonidentical subunits with molecular weights of 63,200 and 36,400. Depolymerase is a highly specific glycanohydrolase which randomly attacks the galactosyl-α-1→3-galactose linkages of the capsular polysaccharide; one susceptible bond occurs in each tetrasaccharide repeating unit of the polymer. Depolymerase activity may be conveniently assayed by the release of reducing groups; the pH optimum of the enzyme is 5.2. Treatment of capsular polysaccharide with NaIO4 and NaBH4 selectively degrades the glucuronate branches; the resultant polysaccharide is digested by depolymerase at less than 1% the rate of native capsular polysaccharide. The smallest oligosaccharide that depolymerase will degrade is a dodecasaccharide, termed C, composed of three tetrasaccharide repeating units. Reduced C is digested by depolymerase at 1% of the rate of capsular polysaccharide and is degraded in a highly specific manner; only the galactosylgalactose linkage immediately adjacent to the terminal, nonreducing tetrasaccharide repeating unit is attacked. The phage-bound and soluble depolymerases are identical with respect to their catalytic properties. Treatment of phage with either 8 m urea or 4 m guanidine·HCl results in quantitative solubilization of the phage-bound depolymerase activity. The solubilized enzyme is indistinguishable from the soluble enzyme isolated from cell lysates as judged by Sephadex G-200 column chromatography.

Galactomannan, Aerobacter aerogenes, depolymerase

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

*O[C@H]1[C@@H](O)[C@@H](CO)O[C@H](O[C@@H]2[C@H](O[C@@H]3O[C@H](C(=O)O)[C@@H](O)[C@H](O)[C@H]3O)[C@@H](O[C@@H]3[C@@H](O)[C@@H](*)O[C@H](CO)[C@@H]3O)O[C@H](CO)[C@H]2O)[C@@H]1O

662.547 g/mol (C₂₄H₃₈R₂O₂₁, R = next and previous repeats, not counted in mol weight)

A capsular polysaccharide produced by Aerobacter aerogenes has been purified and shown to consist of galactose, mannose, and glucuronic acid in a molar ratio of 2:1:1, respectively. Partial acid hydrolysis liberated an aldobiouronic acid identified as 2-O-β-D-glucuronosyl-D-mannose. Analysis of capsular polysaccharide by Smith periodate degradation further indicated that all of the galactose residues are linked through C-3, all of the mannose residues are linked through both C-2 and C-3, and all of the glucuronic acid is at terminal, nonreducing positions. Digestion of capsular polysaccharide with a specific phage-induced polysaccharide depolymerase resulted in its nearly quantitative conversion to two limit oligosaccharides, termed A and B. Partial acid hydrolysis, methylation analysis, and periodate degradation indicated that A is the tetrasaccharide, Gal-1→3-(GlcUA-1→2)-Man-1→3-Gal. B was characterized as an octasaccharide composed of two units of A by the following procedure: Smith periodate degradation of B yielded the pentasaccharide mannosyl-α-galactosyl-α-galactosyl-α-mannosyl-α-lyxitol. This pentasaccharide was characterized and the anomeric configuration of the glycosidic bonds determined by sequential enzymatic degradation with specific exoglycosidases. Further analyses indicated that B is the octasaccharide, Gal-1α→3-(GlcUA-1β→2)-Man-1α→3-Gal-1α→3-Gal-1α→3-(GlcUA-1β→2)-Man-1α→3-Gal. A third oligosaccharide, termed C, was present in small amounts in extensive depolymerase digests of capsular polysaccharide. This oligosaccharide was shown to be a dodecasaccharide composed of three units of A. Exhaustive depolymerase digestion of C resulted in its slow degradation to yield equimolar amounts of A and B. These results indicate that Aerobacter aerogenes capsular polysaccharide is composed of repeating sequences of the following tetrasaccharide. Moreover, they also indicate that the phage-induced polysaccharide depolymerase is a glycanohydrolase which specifically cleaves the galactosyl-1 (α)/→ 3-galactose linkages in the capsular polysaccharide.

Galactomannan, Aerobacter aerogenes, depolymerase

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

*O[C@H]1[C@@H](O)[C@@H](CO)O[C@H](O[C@@H]2[C@H](O[C@@H]3O[C@H](C(=O)O)[C@@H](O)[C@H](O)[C@H]3O)[C@@H](O[C@@H]3[C@@H](O)[C@@H](*)O[C@H](CO)[C@@H]3O)O[C@H](CO)[C@H]2O)[C@@H]1O

662.547 g/mol (C₂₄H₃₈R₂O₂₁, R = next and previous repeats, not counted in mol weight)