{"entity": "publication", "iuid": "9e2c17a080194866b4fd9a2da01237f2", "timestamp": "2026-09-24T01:04:45.554Z", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/9e2c17a080194866b4fd9a2da01237f2.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/9e2c17a080194866b4fd9a2da01237f2"}}, "title": "Importance of individual residues in hydrophobic patch PLVIVGL (1481-1487) in FV-Short for synergistic TFPI\u03b1 cofactor activity with protein S, an alanine-scanning study: AlphaFold-mediated prediction of FV-Short/TFPI\u03b1/protein S trimolecular complex structure.", "authors": [{"family": "Dahlb\u00e4ck", "given": "Bj\u00f6rn", "initials": "B"}, {"family": "Tran", "given": "Sinh", "initials": "S"}, {"family": "Draczkowski", "given": "Piotr", "initials": "P"}], "type": "journal article", "published": "2025-03-00", "journal": {"title": "J. Thromb. Haemost.", "issn": "1538-7836", "volume": "23", "issue": "3", "pages": "849-862", "issn-l": null}, "abstract": "In the splice variant factor (F)V-Short, 702 residues are deleted from the B domain, resulting in exposure of an acid region (AR2; 1493-1537) that binds TFPI\u03b1. FV-Short and protein S serve as synergistic TFPI\u03b1 cofactors in inhibition of FXa. In the preAR2 region, a hydrophobic patch PLVIVGL (1481-1487) is crucial for synergistic TFPI\u03b1-cofactor activity and assembly of FV-Short, TFPI\u03b1, and protein S.\n\nTo elucidate the importance of individual residues in the PLVIVGL patch for synergism between FV-Short and protein S as TFPI\u03b1 cofactors.\n\nAn alanine scanning of the hydrophobic patch was performed in which 7 FV-Short variants were created. The synergistic TFPI\u03b1-cofactor activity was analyzed by FXa inhibition and a microtiter-based assay tested binding between the proteins. AlphaFold 3 was used to predict protein-protein interactions between FV-Short, protein S, and TFPI\u03b1.\n\nFive of the 7 variants (V1483A, I1484A, V1485A, G1486A, and L1487A) demonstrated decreased synergistic TFPI\u03b1 cofactor activity; in particular, G1486A and L1487A were severely affected. Neither wild-type FV-Short nor any of the mutants bound protein S in the absence of TFPI\u03b1. In the presence of TFPI\u03b1, wild-type FV-Short, P1481A, L1482A, and V1485A bound protein S, whereas V1483A, I1484A, G1486A, and L1487A did not. AlphaFold predicted an interaction between the hydrophobic patch in FV-Short and a hydrophobic patch in protein S involving residues 268-276 and 422-426.\n\nIndividual residues (V1483, I1484, G1486, and L1487) in the hydrophobic patch are demonstrated to be important for the synergistic TFPI\u03b1-cofactor activity and for the assembly of a trimolecular FXa-inhibitory complex.", "doi": "10.1016/j.jtha.2024.11.013", "pmid": "39617184", "labels": [], "xrefs": [{"db": "pii", "key": "S1538-7836(24)00703-7"}], "notes": [], "created": "2026-09-23T13:22:22.844Z", "modified": "2026-09-23T13:22:22.872Z"}