Structural elucidation of the novel core oligosaccharide from LPS of Burkholderia cepacia serogroup O4
Bibliographic record
Abstract
Lipopolysaccharide (LPS) is an important virulence factor of Burkholderia cepacia, an opportunistic bacterial pathogen that causes life-threatening disease in cystic fibrosis patients and immunocompromised individuals. B. cepacia LPS comprises an O-specific polysaccharide covalently linked to a core oligosaccharide (OS) which in turn is attached to a lipid A moiety. The complete structure of the LPS core oligosaccharide from B. cepacia serotype O4 was investigated by detailed NMR and mass spectrometry (MS) methods. High- (HMW) and low-molecular-weight (LMW) OSs were obtained by deacylation, dephosphorylation, and reducing-end reduction of the LPS. Glycan and NMR analyses established that both OSs contain a common inner-core structure consisting of D-glucose, L-glycero-D-manno-heptose, D-glycero-D-manno-heptose, 3-deoxy-D-manno-octulsonic acid, and D-glycero-D-talo-2-octulosonic acid. The structure of the LMW OS differed from that of the HMW OS in that it lacks a tetra-rhamnosyl GlcNAc OS extension. These structural conclusions were confirmed by tandem MS analyses of the two OS fractions as well as an OS fraction obtained by alkaline deacylation of the LPS. The location of a phosphoethanolamine substituent in the core region was determined by ESI-MS and methylation analysis of O-deacylated LPS and core OS samples. A polyclonal antibody to B. cepacia serotype O4 core OS was cross-reactive with several other serotypes indicating common structural features.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".