𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Structure of the O-deacetylated glucuronoxylomannan from Cryptococcus neoformans Cap70 as determined by 2D NMR spectroscopy

✍ Scribed by Bradley E. Bacon; Robert Cherniak; Kyung J. Kwon-Chung; Eric S. Jacobson

Publisher
Elsevier Science
Year
1996
Tongue
English
Weight
1014 KB
Volume
283
Category
Article
ISSN
0008-6215

No coin nor oath required. For personal study only.

✦ Synopsis

Cryptococcus neoformans, an opportunistic pathogen, is the fourth leading cause of death among AIDS patients. The yeast's capsule is a major virulence factor, and serotype is related to the chemical structure of glucuronoxylomannan (GXM), its capsular polysaccharide. The GXM from Cap70, a hypocapsular mutant of serotype D isolate B-3501, was investigated by chemical analysis and 2D NMR spectroscopy. The assignment of 1H and 13C chemical shifts for the O-deacetylated polysaccharide was accomplished from the analysis of DQF-COSY, TOCSY, and gradient-enhanced HSQC spectra. The sequence and linkage positions of glycosyl residues were determined by NOESY and ROESY spectra. Two repeating polysaccharide components were identified as having the following structures in approximately equal proportions: [formula: see text] It is not known if these repeating units comprise a single or two separate polymer chains. Pentasaccharide 2 has been known to be the major GXM polymer of B-3501 and other serotype D isolates. Hexasaccharide 1 is identified for the first time although it has subsequently been identified in other C. neoformans isolates. The presence of 1 in the GXM of Cap70 is consistent with the extra xylose found relative to that in isolate B-3501. The mannose:xylose:glucuronic acid:O-acetyl molar ratio of Cap70 GXM is 3.00:1.73:0.78:1.75, while the same ratio for B-3501 and other serotype D isolates is approximately 3.00:1.00:0.80:1.75. Methylation analysis confirmed that the GXM of Cap70 contains unsubstituted, monosubstituted (2-linked), and disubstituted (2- and 4-linked) mannose in a ratio of 0.87:1.75:0.38. Dot blot immunoassay indicates that Cap70 is a serotype D isolate like its parent strain.

📜 SIMILAR VOLUMES

Structure of the De-O-acetylated glucuro
Structure of the De-O-acetylated glucuronoxylomannan from Cryptococcus neoformans serotype D, as determined by 2D NMR spectroscopy
✍ Marshall A. Skelton; Robert Cherniak; Leszek Poppe; Herman van Halbeek 📂 Article 📅 1991 🏛 John Wiley and Sons 🌐 English ⚖ 738 KB

## Abstract The primary structure of the de‐__O__‐acetylated glucuronoxylomannan isolated from __Cryptococcus neoformans__ serotype D was characterized __de novo__ by NMR spectroscopy. Assignment of the ^1^H and ^13^C spectra of the polysaccharide involved a combination of 2D NMR experiments includ

Proton assignment and structural feature
Proton assignment and structural features of a peptide from the chymosin-sensitive region of bovine k-casein determined by 2D-NMR spectroscopy
✍ Jeffrey E. Plowman; Mark H. Smith; Lawrence K. Creamer; Michael J. Liddell; Jan 📂 Article 📅 1994 🏛 John Wiley and Sons 🌐 English ⚖ 682 KB

## Abstract The peptide __k__‐casein(98–111) corresponding to the sequence 98–111 of bovine __k__‐casein (His‐Pro‐His‐Pro‐His‐Leu‐Ser‐Phe‐Met‐Ala‐Ile‐Pro‐Pro‐Lys), which includes the aspartic protease sensitive region, was analysed by 2D ^1^H NMR spectroscopic techniques in DMSO‐__d__~6~. The spect

Structural determination of aspericins A
Structural determination of aspericins AC, new furan and pyran derivates from the marine-derived fungus Rhizopus sp. 2-PDA-61, by 1D and 2D NMR spectroscopy
✍ Fazuo Wang; Tianjiao Zhu; Min Zhang; Aiqun Lin; Weiming Zhu; Qianqun Gu 📂 Article 📅 2009 🏛 John Wiley and Sons 🌐 English ⚖ 102 KB

## Abstract Three new furan and pyran derivatives named aspericins AC (1–3), as well as a known asperic acid (4), have been isolated from the marine‐derived fungus __Rhizopus__ sp. 2‐PDA‐61. The complete ^1^H and ^13^C NMR assignments for the new compounds were carried out using ^1^H, ^13^C, DEPT,