Purification of Human Kallikrein 6 from Biological Fluids and Identification of its Complex with α1-Antichymotrypsin
Bibliographic record
Abstract
BACKGROUND: Human kallikrein 6 (hK6) is significantly increased in serum in many patients with ovarian cancer and may have a role in amyloid precursor processing and Alzheimer disease. The forms of hK6 in biological fluids are poorly characterized. METHODS: hK6 protein was immunoaffinity-purified and positively identified by Western blotting, N-terminal sequencing, and mass spectrometry. hK6 in cerebrospinal fluid (CSF), milk, ascites, and serum was size-fractionated by chromatography and then measured by a highly sensitive and specific immunoassay. Hybrid assays were performed to detect the possible interactions between hK6 and proteinase inhibitors in CSF, milk, ascites fluid, and serum. RESULTS: N-Terminal sequencing identified hK6 in the proform in both CSF and milk. hK6 exists in two forms in milk and ascites fluid: a free form with a molecular mass of approximately 25 kDa and a higher molecular mass form. Hybrid sandwich assays (capture antibody for hK6 and detection antibody for inhibitors), utilizing a panel of known serine protease inhibitors, indicated that alpha(1)-antichymotrypsin forms a complex with hK6 in milk and ascites fluid. Only the free form of hK6 was detected in CSF and serum. CONCLUSIONS: hK6 exists mainly as a proenzyme in milk and CSF. A fraction of this enzyme is partially complexed with alpha(1)-antichymotrypsin in milk and ascites fluid of ovarian cancer patients.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 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) | 0.001 | 0.001 |
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".