4LFS
High resolution x-ray structure of racemic ShK toxin
Summary for 4LFS
| Entry DOI | 10.2210/pdb4lfs/pdb |
| Related | 4LFQ |
| Descriptor | Potassium channel toxin ShK, CHLORIDE ION, GLYCEROL, ... (4 entities in total) |
| Functional Keywords | shk toxin, chemical protein synthesis, racemic protein crystallography, toxin |
| Biological source | Stichodactyla helianthus (Carribean sea anemone) |
| Cellular location | Secreted: P29187 |
| Total number of polymer chains | 1 |
| Total formula weight | 4303.80 |
| Authors | Dang, B.,Kubota, T.,Mandal, K.,Bezanilla, F.,Kent, S.B.H. (deposition date: 2013-06-27, release date: 2013-08-14, Last modification date: 2023-12-27) |
| Primary citation | Dang, B.,Kubota, T.,Mandal, K.,Bezanilla, F.,Kent, S.B. Native Chemical Ligation at Asx-Cys, Glx-Cys: Chemical Synthesis and High-Resolution X-ray Structure of ShK Toxin by Racemic Protein Crystallography. J.Am.Chem.Soc., 135:11911-11919, 2013 Cited by PubMed Abstract: We have re-examined the utility of native chemical ligation at -Gln/Glu-Cys- [Glx-Cys] and -Asn/Asp-Cys- [Asx-Cys] sites. Using the improved thioaryl catalyst 4-mercaptophenylacetic acid (MPAA), native chemical ligation could be performed at -Gln-Cys- and Asn-Cys- sites without side reactions. After optimization, ligation at a -Glu-Cys- site could also be used as a ligation site, with minimal levels of byproduct formation. However, -Asp-Cys- is not appropriate for use as a site for native chemical ligation because of formation of significant amounts of β-linked byproduct. The feasibility of native chemical ligation at -Gln-Cys- enabled a convergent total chemical synthesis of the enantiomeric forms of the ShK toxin protein molecule. The D-ShK protein molecule was ~50,000-fold less active in blocking the Kv1.3 channel than the L-ShK protein molecule. Racemic protein crystallography was used to obtain high-resolution X-ray diffraction data for ShK toxin. The structure was solved by direct methods and showed significant differences from the previously reported NMR structures in some regions of the ShK protein molecule. PubMed: 23919482DOI: 10.1021/ja4046795 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (0.97 Å) |
Structure validation
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