{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,27]],"date-time":"2025-10-27T04:47:54Z","timestamp":1761540474186},"reference-count":0,"publisher":"Georg Thieme Verlag KG","issue":"01","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Thromb Haemost"],"published-print":{"date-parts":[[2004]]},"abstract":"<jats:title>Summary<\/jats:title><jats:p>The contribution of the factor Va C1 domain (fVa-C1) to assembly of the prothrombinase complex has not been previously investigated. The homologous fVa-C2 domain contains a binding site for phosphatidylserine (PS) that includes the indole moieties of Trp2063\/Trp2064 at the apex of spike-1. In order to investigate the structure and function of fVa-C1 a molecular model was constructed based on the structure of fVa-C2. The aromatic and hydrophobic side chains of Tyr1956\/Leu1957 in fVaC1 are located at the predicted apex of spike-3. Exposed charged and hydrophobic residues in fVa-C1 were changed to alanine in clusters of 1-3 mutations per construct. The resultant 20 mutants were expressed in COS cells and screened for binding to immobilized PS and prothrombinase activity on phospholipid vesicles containing either 25% or 5% PS. Two mutants, (Y1956,L1957)A, and (R2023,R2027)A showed both decreased binding to immobilized PS and a selective decrease in prothrombinase activity on membranes containing 5% PS. The interaction of purified (Y1956,L1957)A with phospholipid vesicles was studied using fluorescence resonance energy transfer and prothrombinase assays. The affinity of (Y1956,L1957)A binding to 25% PS membranes was reduced 12-fold compared to rHFVa. Prothrombin activation in the presence of (Y1956,L1957)A was markedly impaired on phospholipid vesicles containing 10% or less PS. We conclude that solvent exposed hydrophobic and aromatic amino acids in both fVa-C1 and fVa-C2 contribute to the interaction of factor V with PS membranes.<\/jats:p>","DOI":"10.1160\/th03-04-0222","type":"journal-article","created":{"date-parts":[[2003,11,6]],"date-time":"2003-11-06T09:22:53Z","timestamp":1068110573000},"page":"16-27","source":"Crossref","is-referenced-by-count":39,"title":["The factor V C1 domain is involved in membrane binding: identification of functionally important amino acid residues within the C1 domain of factor V using alanine scanning mutagenesis"],"prefix":"10.1160","volume":"91","author":[{"given":"Mary","family":"Quinn-Allen","sequence":"first","affiliation":[]},{"given":"Sandra","family":"Macedo-Ribeiro","sequence":"first","affiliation":[]},{"given":"Pablo","family":"Fuentes-Prior","sequence":"first","affiliation":[]},{"given":"Wolfram","family":"Bode","sequence":"first","affiliation":[]},{"given":"Mahasen","family":"Saleh","sequence":"additional","affiliation":[]},{"given":"Weimin","family":"Peng","sequence":"additional","affiliation":[]},{"given":"William","family":"Kane","sequence":"additional","affiliation":[]}],"member":"194","published-online":{"date-parts":[[2017,11,30]]},"container-title":["Thrombosis and Haemostasis"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/www.thieme-connect.de\/products\/ejournals\/pdf\/10.1160\/TH03-04-0222.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2018,10,24]],"date-time":"2018-10-24T15:33:26Z","timestamp":1540395206000},"score":1,"resource":{"primary":{"URL":"http:\/\/www.thieme-connect.de\/DOI\/DOI?10.1160\/TH03-04-0222"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2004]]},"references-count":0,"journal-issue":{"issue":"01","published-online":{"date-parts":[[2017,12,15]]},"published-print":{"date-parts":[[2004]]}},"URL":"https:\/\/doi.org\/10.1160\/th03-04-0222","relation":{},"ISSN":["0340-6245","2567-689X"],"issn-type":[{"value":"0340-6245","type":"print"},{"value":"2567-689X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2004]]}}}