In Vitro Activity of Neisseria meningitidis PglL O-Oligosaccharyltransferase with Diverse Synthetic Lipid Donors and a UDP-activated Sugar
Bibliographic record
Abstract
Oligosaccharyltransferases (OTases) are enzymes that catalyze the transfer of an oligosaccharide from a lipid carrier to an acceptor molecule, commonly a protein. OTases are classified as N-OTases and O-OTases, depending on the nature of the glycosylation reaction. The N-OTases catalyze the glycan transfer to amide groups in asparagines in a reaction named N-linked glycosylation. The O-OTases are responsible for protein O-linked glycosylation, which involves the attachment of glycans to hydroxyl groups of serine or threonine residues. These enzymes exhibit a relaxed specificity and are able to transfer a variety of glycan structures to different protein acceptors. This property confers OTases with great biotechnological potential as these enzymes can produce glycoconjugates relevant to the pharmaceutical industry. Furthermore, OTases are thought to be involved in pathogenesis mechanisms. Several aspects of the functionality of OTases are not fully understood. In this work, we developed a novel approach to perform kinetic studies on PglL, the O-OTase from Neisseria meningitidis. We investigated the importance of the acyl moiety of the lipid glycan donor substrate on the functionality of PglL by testing the efficiency of glycosylation reactions using synthetic substrates carrying the same glycan structure but different acyl moieties. We found that PglL can function with many lipids as glycan donors, although the length and the conformation of the lipid moiety significantly influenced the catalytic efficiency. Interestingly, PglL was also able to transfer a monosaccharide employing its nucleotide-activated form, acting as a Leloir glycosyltransferase. These results provide new insights on the function and the evolution of oligosaccharyltransferases.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".