Kunitz-type protease inhibitor 1 (SPINT1) is a 529-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: O43278.
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The mean pLDDT of this model is 76.2 (confident overall). pLDDT is AlphaFold's per-residue confidence score from 0 to 100. In MolViewer, choose the B-factor color scheme to color the model by pLDDT, because AlphaFold stores it in the B-factor column.
| pLDDT band | Meaning | Share of residues |
|---|---|---|
| Above 90 | Very high: backbone and side chains are usually accurate | 36% |
| 70 to 90 | Confident: backbone generally right | 35% |
| 50 to 70 | Low: treat with caution | 9% |
| Below 50 | Very low: often disordered regions | 20% |
What pLDDT means and how to read it
Inhibitor of HGFAC (PubMed:9045658). Inhibits serine protease activity of ST14/matriptase in vitro (PubMed:28710277). Inhibits serine protease activity of TMPRSS13, via the BPTI/Kunitz inhibitor 1 domain (PubMed:20977675)
Interacts with HGFAC (PubMed:15713485). Interacts with TMPRSS13; the interaction promotes the phosphorylation and cell membrane localization of TMPRSS13 (PubMed:28710277)
Secreted, Cytoplasm, Cell membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 4ISO | X-ray | 2.01 Å | B=245-304 |
| 5EZD | X-ray | 2.1 Å | A/B=168-303 |
| 4ISL | X-ray | 2.29 Å | B=245-304 |
| 4ISN | X-ray | 2.45 Å | B=245-305 |
| 1YC0 | X-ray | 2.6 Å | I=245-303 |
| 5H7V | X-ray | 3.82 Å | A=36-457 |
| 2MSX | NMR | A=47-152 |
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