2NH and 3OH are crucial structural requirements in sphingomyelin for sticholysin II binding and pore formation in bilayer membranes

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)


Interna författare/redaktörer


Publikationens författare: Maula T, Isaksson YJE, Garcia-Linares S, Niinivehmas S, Pentikainen OT, Kurita M, Yamaguchi S, Yamamoto T, Katsumura S, Gavilanes JG, Martinez-del-Pozo A, Slotte JP
Förläggare: ELSEVIER SCIENCE BV
Publiceringsår: 2013
Tidskrift: BBA - Biomembranes
Tidskriftsakronym: BBA-BIOMEMBRANES
Volym: 1828
Nummer: 5
Artikelns första sida, sidnummer: 1390
Artikelns sista sida, sidnummer: 1395
Antal sidor: 6
ISSN: 0005-2736
eISSN: 1879-2642


Abstrakt

Sticholysin II (StnII) is a pore-forming toxin from the sea anemone Stichodactyla heliantus which belongs to the large actinoporin family. The toxin binds to sphingomyelin (SM) containing membranes, and shows high binding specificity for this lipid. In this study, we have examined the role of the hydrogen bonding groups of the SM long-chain base (i.e., the 2NH and the 3OH) for StnII recognition. We prepared methylated SM-analogs which had reduced hydrogen bonding capability from 2NH and 3OH. Both surface plasmon resonance experiments, and isothermal titration calorimetry measurements indicated that Stall failed to bind to bilayers containing methylated SM-analogs, whereas clear binding was seen to SM-containing bilayers. Stall also failed to induce calcein release (i.e., pore formation) from vesicles made to contain methylated SM-analogs, but readily induced calcein release from SM-containing vesicles. Molecular modeling of SM docked to the phosphocholine binding site of StnII indicated that the 2NH and 3OH groups were likely to form a hydrogen bond with Tyr135. In addition, it appeared that Tyr111 and Tyr136 could donate hydrogen bonds to phosphate oxygen, thus stabilizing SM binding to the toxin. We conclude that the interfacial hydrogen bonding properties of SM, in addition to the phosphocholine head group, are crucial for high-affinity SM/StnII-interaction. (C) 2013 Elsevier B.V. All rights reserved.


Nyckelord

Isothermal titration calorimetry, Membrane permeabilization, Molecular docking, Surface plasmon resonance

Senast uppdaterad 2019-21-10 vid 03:23