Person:
García Linares, Sara

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First Name
Sara
Last Name
García Linares
URI
https://hdl.handle.net/20.500.14352/85452
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Biológicas
Department
Bioquímica y Biología Molecular
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2015 - 201912020 - 20211
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Author: Gavilanes, José G. × Subject: 577.2 ×

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Now showing 1 - 2 of 2
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    Structural foundations of sticholysin functionality
    (BBA - Proteins and Proteomics, 2021) Palacios Ortega, Juan; García Linares, Sara; Rivera de Torre, Esperanza; Heras Márquez, Diego; Gavilanes, José G.; Peter, Slotte; Martínez del Pozo, Álvaro
    Actinoporins constitute a family of α pore-forming toxins produced by sea anemones. The soluble fold of these proteins consists of a β-sandwich flanked by two α-helices. Actinoporins exert their activity by specifically recognizing sphingomyelin at their target membranes. Once there, they penetrate the membrane with their N-terminal α-helices, a process that leads to the formation of cation-selective pores. These pores kill the target cells by provoking an osmotic shock on them. In this review, we examine the role and relevance of the structural features of actinoporins, down to the residue level. We look at the specific amino acids that play significant roles in the function of actinoporins and their fold. Particular emphasis is given to those residues that display a high degree of conservation across the actinoporin sequences known to date. In light of the latest findings in the field, the membrane requirements for pore formation, the effect of lipid composition, and the process of pore formation are also discussed.
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    Cholesterol stimulates and ceramide inhibits Sticholysin II-induced pore formation in complex bilayer membranes
    (BBA - Biochimica et Biophysica Acta, 2015) Alm, Ida; García Linares, Sara; Gavilanes, José G.; Martínez del Pozo, Álvaro; Slotte, J. Peter
    The pore forming capacity of Sticholysin II (StnII; isolated from Stichodactyla helianthus) in bilayer membranes containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), palmitoylsphingomyelin (PSM) and either cholesterol or palmitoyl ceramide (PCer) has been examined. The aim of the study was to elucidate how the presence of differently ordered PSM domains affected StnII oligomerization and pore formation. Cholesterol is known to enhance pore formation by StnII, and our results confirmed this and provide kinetic information for the process. The effect of cholesterol on bilayer permeabilization kinetics was concentration-dependent. In the concentration regime used (2.5–10 nmol cholesterol in POPC:PSM 80:20 by nmol), cholesterol also increased the acyl chain order in the fluid PSM domain and thus decreased bilayer fluidity, suggesting that fluidity per se was not responsible for cholesterol's effect. Addition of PCer (2.5–10 nmol) to the POPC:PSM (80:20 by nmol) bilayers attenuated StnII-induced pore formation, again in a concentration-dependent fashion. This addition also led to the formation of a PCer-rich gel phase. Addition of cholesterol to PCer-containing membranes could partially reduce the inhibitory effect of PCer on StnII pore formation. We conclude that the physical state of PSM (as influenced by either cholesterol or PCer) affected StnII binding and pore formation under the conditions examined.