TY - JOUR
T1 - Determination of the boundary lipids of sticholysins using tryptophan quenching
AU - Palacios-Ortega, Juan
AU - Amigot-Sánchez, Rafael
AU - García-Montoya, Carmen
AU - Gorše, Ana
AU - Heras-Márquez, Diego
AU - García-Linares, Sara
AU - Martínez-del-Pozo, Álvaro
AU - Slotte, J. Peter
N1 - Funding Information:
This research was supported by the Juselius Foundation (J.P.S. and J.P.-O.) and by UCM-Banco Santander Grants PR75/18-21561, PR87/19-22556, and PR108/20-26896 (to A.M.-d.-P.). This work is also under the auspices of UnaEuropa-2021 (seed funding number SF-2106). D.H.-M has a Complutense University of Madrid and Banco Santander PhD fellowship (CT82/20 / CT83/20). For most of the conduct of this study, J.P.-O. had a funded doctoral student position from ISB/ÅA. For the final part, J.P.-O. enjoyed a postdoctoral grant from the Magnus Ehrnrooth Foundation.
Funding Information:
This research was supported by the Juselius Foundation (J.P.S. and J.P.-O.) and by UCM-Banco Santander Grants PR75/18-21561, PR87/19-22556, and PR108/20-26896 (to A.M.-d.-P.). This work is also under the auspices of UnaEuropa-2021 (seed funding number SF-2106). D.H.-M has a Complutense University of Madrid and Banco Santander PhD fellowship (CT82/20 / CT83/20). For most of the conduct of this study, J.P.-O. had a funded doctoral student position from ISB/ÅA. For the final part, J.P.-O. enjoyed a postdoctoral grant from the Magnus Ehrnrooth Foundation.
Publisher Copyright:
© 2022, The Author(s).
PY - 2022/12
Y1 - 2022/12
N2 - Sticholysins are α-pore-forming toxins produced by the sea-anemone Stichodactyla helianthus. These toxins exert their activity by forming pores on sphingomyelin-containing membranes. Recognition of sphingomyelin by sticholysins is required to start the process of pore formation. Sphingomyelin recognition is coupled with membrane binding and followed by membrane penetration and oligomerization. Many features of these processes are known. However, the extent of contact with each of the different kinds of lipids present in the membrane has received little attention. To delve into this question, we have used a phosphatidylcholine analogue labeled at one of its acyl chains with a doxyl moiety, a known quencher of tryptophan emission. Here we present evidence for the contact of sticholysins with phosphatidylcholine lipids in the sticholysin oligomer, and for how each sticholysin isotoxin is affected differently by the inclusion of cholesterol in the membrane. Furthermore, using phosphatidylcholine analogs that were labeled at different positions of their structure (acyl chains and headgroup) in combination with a variety of sticholysin mutants, we also investigated the depth of the tryptophan residues of sticholysins in the bilayer. Our results indicate that the position of the tryptophan residues relative to the membrane normal is deeper when cholesterol is absent from the membrane.
AB - Sticholysins are α-pore-forming toxins produced by the sea-anemone Stichodactyla helianthus. These toxins exert their activity by forming pores on sphingomyelin-containing membranes. Recognition of sphingomyelin by sticholysins is required to start the process of pore formation. Sphingomyelin recognition is coupled with membrane binding and followed by membrane penetration and oligomerization. Many features of these processes are known. However, the extent of contact with each of the different kinds of lipids present in the membrane has received little attention. To delve into this question, we have used a phosphatidylcholine analogue labeled at one of its acyl chains with a doxyl moiety, a known quencher of tryptophan emission. Here we present evidence for the contact of sticholysins with phosphatidylcholine lipids in the sticholysin oligomer, and for how each sticholysin isotoxin is affected differently by the inclusion of cholesterol in the membrane. Furthermore, using phosphatidylcholine analogs that were labeled at different positions of their structure (acyl chains and headgroup) in combination with a variety of sticholysin mutants, we also investigated the depth of the tryptophan residues of sticholysins in the bilayer. Our results indicate that the position of the tryptophan residues relative to the membrane normal is deeper when cholesterol is absent from the membrane.
UR - http://www.scopus.com/inward/record.url?scp=85139888162&partnerID=8YFLogxK
U2 - 10.1038/s41598-022-21750-y
DO - 10.1038/s41598-022-21750-y
M3 - Article
C2 - 36243747
AN - SCOPUS:85139888162
SN - 2045-2322
VL - 12
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 17328
ER -