tailieunhanh - Báo cáo khoa học: Biochemical characterization of annexin B1 from Cysticercus cellulosae

Annexin B1 fromCysticercus cellulosaehas recently been identified using immunological screening in an attempt to find novel antigens for vaccine development against cysticercosis. The protein possesses anticoagulant activity and carries significant therapeutic potential due to its thrombus-targeting and thrombolytic properties. | iFEBS Journal Biochemical characterization of annexin B1 from Cysticercus cellulosae Anja Winter1 Adlina M. Yusof1 Erning Gao1 Hong-Li Yan2 and Andreas Hofmann1 1 Institute of Structural Molecular Biology Schoolof BiologicalSciences The University of Edinburgh UK 2 Department of MedicalGenetics The Second Military MedicalUniversity Shanghai China Keywords annexins calcium heparin protein-glycosaminoglycan interactions proteinmembrane interactions Correspondence A. Hofmann Institute of Structural Molecular Biology Schoolof Biological Sciences The University of Edinburgh The King s Buildings Mayfield Road Edinburgh EH9 3JR UK Fax 44 131 650 8650 Tel 44 131 650 5365 E-mail Received 7 March 2006 revised 7 April 2006 accepted 22 May 2006 doi Annexin B1 from Cysticercus cellulosae has recently been identified using immunological screening in an attempt to find novel antigens for vaccine development against cysticercosis. The protein possesses anticoagulant activity and carries significant therapeutic potential due to its thrombustargeting and thrombolytic properties. We investigated the biochemical properties of annexin B1 using liposome and heparin Sepharose copelleting assays as well as CD spectroscopy. The calcium-dependent binding to acidic phospholipid membranes is reminiscent of other mammalian annexins with a clear preference for high phosphatidylserine content. A unique property of annexin B1 is its ability to bind to liposomes with high phosphatidylserine content in the absence of calcium which might be due to the presence of several basic residues on the convex protein surface that harbours the membrane-binding loops. Annexin B1 demonstrates lectin properties and binds to heparin Sepharose in a cooperative calcium-dependent manner. Although this binding is reversible to a large extent a small fraction of the protein remains bound to the glycosaminoglycan even in the presence of high concentrations of .