Force Mapping Study of Actinoporin Effect in Membranes Presenting Phase Domains
Equinatoxin II (EqtII) and Fragaceatoxin C (FraC) are pore-forming toxins (PFTs) from the actinoporin family that have enhanced membrane affinity in the presence of sphingomyelin (SM) and phase coexistence in the membrane. However, little is known about the effect of these proteins on the nanoscopic...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-09-01
|
| Series: | Toxins |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-6651/13/9/669 |
| _version_ | 1797517043025575936 |
|---|---|
| author | Katia Cosentino Edward Hermann Nicolai von Kügelgen Joseph D. Unsay Uris Ros Ana J. García-Sáez |
| author_facet | Katia Cosentino Edward Hermann Nicolai von Kügelgen Joseph D. Unsay Uris Ros Ana J. García-Sáez |
| author_sort | Katia Cosentino |
| collection | DOAJ |
| description | Equinatoxin II (EqtII) and Fragaceatoxin C (FraC) are pore-forming toxins (PFTs) from the actinoporin family that have enhanced membrane affinity in the presence of sphingomyelin (SM) and phase coexistence in the membrane. However, little is known about the effect of these proteins on the nanoscopic properties of membrane domains. Here, we used combined confocal microscopy and force mapping by atomic force microscopy to study the effect of EqtII and FraC on the organization of phase-separated phosphatidylcholine/SM/cholesterol membranes. To this aim, we developed a fast, high-throughput processing tool to correlate structural and nano-mechanical information from force mapping. We found that both proteins changed the lipid domain shape. Strikingly, they induced a reduction in the domain area and circularity, suggesting a decrease in the line tension due to a lipid phase height mismatch, which correlated with proteins binding to the domain interfaces. Moreover, force mapping suggested that the proteins affected the mechanical properties at the edge, but not in the bulk, of the domains. This effect could not be revealed by ensemble force spectroscopy measurements supporting the suitability of force mapping to study local membrane topographical and mechanical alterations by membranotropic proteins. |
| first_indexed | 2024-03-10T07:09:19Z |
| format | Article |
| id | doaj.art-137e32d22154401e8999f87bace83da8 |
| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-03-10T07:09:19Z |
| publishDate | 2021-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Toxins |
| spelling | doaj.art-137e32d22154401e8999f87bace83da82023-11-22T15:31:47ZengMDPI AGToxins2072-66512021-09-0113966910.3390/toxins13090669Force Mapping Study of Actinoporin Effect in Membranes Presenting Phase DomainsKatia Cosentino0Edward Hermann1Nicolai von Kügelgen2Joseph D. Unsay3Uris Ros4Ana J. García-Sáez5Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, GermanyInterfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, GermanyInterfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, GermanyInterfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, GermanyInterfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, GermanyInterfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, GermanyEquinatoxin II (EqtII) and Fragaceatoxin C (FraC) are pore-forming toxins (PFTs) from the actinoporin family that have enhanced membrane affinity in the presence of sphingomyelin (SM) and phase coexistence in the membrane. However, little is known about the effect of these proteins on the nanoscopic properties of membrane domains. Here, we used combined confocal microscopy and force mapping by atomic force microscopy to study the effect of EqtII and FraC on the organization of phase-separated phosphatidylcholine/SM/cholesterol membranes. To this aim, we developed a fast, high-throughput processing tool to correlate structural and nano-mechanical information from force mapping. We found that both proteins changed the lipid domain shape. Strikingly, they induced a reduction in the domain area and circularity, suggesting a decrease in the line tension due to a lipid phase height mismatch, which correlated with proteins binding to the domain interfaces. Moreover, force mapping suggested that the proteins affected the mechanical properties at the edge, but not in the bulk, of the domains. This effect could not be revealed by ensemble force spectroscopy measurements supporting the suitability of force mapping to study local membrane topographical and mechanical alterations by membranotropic proteins.https://www.mdpi.com/2072-6651/13/9/669pore forming toxinsatomic force microscopyforce spectroscopymembrane phase domains |
| spellingShingle | Katia Cosentino Edward Hermann Nicolai von Kügelgen Joseph D. Unsay Uris Ros Ana J. García-Sáez Force Mapping Study of Actinoporin Effect in Membranes Presenting Phase Domains Toxins pore forming toxins atomic force microscopy force spectroscopy membrane phase domains |
| title | Force Mapping Study of Actinoporin Effect in Membranes Presenting Phase Domains |
| title_full | Force Mapping Study of Actinoporin Effect in Membranes Presenting Phase Domains |
| title_fullStr | Force Mapping Study of Actinoporin Effect in Membranes Presenting Phase Domains |
| title_full_unstemmed | Force Mapping Study of Actinoporin Effect in Membranes Presenting Phase Domains |
| title_short | Force Mapping Study of Actinoporin Effect in Membranes Presenting Phase Domains |
| title_sort | force mapping study of actinoporin effect in membranes presenting phase domains |
| topic | pore forming toxins atomic force microscopy force spectroscopy membrane phase domains |
| url | https://www.mdpi.com/2072-6651/13/9/669 |
| work_keys_str_mv | AT katiacosentino forcemappingstudyofactinoporineffectinmembranespresentingphasedomains AT edwardhermann forcemappingstudyofactinoporineffectinmembranespresentingphasedomains AT nicolaivonkugelgen forcemappingstudyofactinoporineffectinmembranespresentingphasedomains AT josephdunsay forcemappingstudyofactinoporineffectinmembranespresentingphasedomains AT urisros forcemappingstudyofactinoporineffectinmembranespresentingphasedomains AT anajgarciasaez forcemappingstudyofactinoporineffectinmembranespresentingphasedomains |