Zika NS5 RdRp Histidine-Thioredoxin tagged construct small scale expression and purification protocol v1
Bibliographic record
Abstract
We present a comprehensive small-scale (<6L) protocol for the expression and purification of the Zika virus NS5 RNA-dependent RNA polymerase (RdRp) domain with an N-terminal His-Trx (Histidine-Thioredoxin) tag. Using the BL21(DE3)-RR E. coli expression system, the protocol describes bacterial transformation, protein induction with IPTG, and a three-step purification process including immobilized metal affinity chromatography (IMAC), TEV protease-mediated tag cleavage, and size-exclusion chromatography. This method yields purified, functional Zika NS5 RdRp suitable for structural studies and antiviral drug screening. The His-Trx tag enhances protein solubility while allowing efficient separation of the cleaved target protein. Special attention is given to preventing degradation of this inherently unstable protein through optimized buffer conditions and expedited purification at low temperatures. The resulting protein can be concentrated to approximately 7 mg/mL and stored at -80°C in small aliquots to minimize freeze-thaw cycles.
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 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.014 | 0.020 |
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".