Immunoglobulin kappa variable 1-33 (IGKV1-33) is a 117-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P01594.
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The mean pLDDT of this model is 91.3 (very high 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 | 79% |
| 70 to 90 | Confident: backbone generally right | 4% |
| 50 to 70 | Low: treat with caution | 16% |
| Below 50 | Very low: often disordered regions | 1% |
What pLDDT means and how to read it
V region of the variable domain of immunoglobulin light chains that participates in the antigen recognition (PubMed:24600447). Immunoglobulins, also known as antibodies, are membrane-bound or secreted glycoproteins produced by B lymphocytes. In the recognition phase of humoral immunity, the membrane-bound immunoglobulins serve as receptors which, upon binding of a specific antigen, trigger the clonal expansion and differentiation of B lymphocytes into immunoglobulins-secreting plasma cells. Secreted immunoglobulins mediate the effector phase of humoral immunity, which results in the elimination of bound antigens (PubMed:20176268, PubMed:22158414). The antigen binding site is formed by the…
Immunoglobulins are composed of two identical heavy chains and two identical light chains; disulfide-linked
Secreted, Cell membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 2Q20 | X-ray | 1.3 Å | A/B=23-117 |
| 3CDC | X-ray | 1.53 Å | A/B=23-117 |
| 3CDF | X-ray | 1.53 Å | A/B/C/D/E/F=23-117 |
| 1B0W | X-ray | 1.8 Å | A/B/C=23-117 |
| 1QP1 | X-ray | 2.06 Å | A/B/C=23-117 |
| 1JV5 | X-ray | 2.2 Å | A=23-117 |
| 3CDY | X-ray | 2.43 Å | A/B=23-117 |
| 7CZQ | EM | 2.8 Å | K/N=24-117 |
| 4K07 | X-ray | 2.83 Å | A/B/C/D/E/F/G/H/I/J=3-117 |
| 7CZV | EM | 3.3 Å | K/M/N=24-117 |
| 7CZU | EM | 3.4 Å | K/N=24-117 |
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