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Protein-lipid interaction of cytolytic toxin Cyt2Aa2 on model lipid bilayers of erythrocyte cell membrane
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Document Title
Protein-lipid interaction of cytolytic toxin Cyt2Aa2 on model lipid bilayers of erythrocyte cell membrane
Author
Tharad S., Promdonkoy B., Toca-Herrera J.L.
Name from Authors Collection
Affiliations
Institute for Biophysics, Department of Nanobiotechnology, University of Natural Resources and Life Sciences (BOKU), Vienna, 1190, Austria; National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathumthani, 12120, Thailand
Type
Article
Source Title
Toxins
ISSN
20726651
Year
2020
Volume
12
Issue
4
Open Access
All Open Access, Gold, Green
Publisher
MDPI AG
DOI
10.3390/toxins12040226
Format
Abstract
Cytolytic toxin (Cyt) is a toxin among Bacillus thuringiensis insecticidal proteins. Cyt toxin directly interacts with membrane lipids for cytolytic action. However, low hemolytic activity is desired to avoid non-specific effects in mammals. In this work, the interaction between Cyt2Aa2 toxin and model lipid bilayers mimicking the erythrocyte membrane was investigated for Cyt2Aa2 wild type (WT) and the T144A mutant, a variant with lower hemolytic activity. Quartz crystal microbalance with dissipation (QCM-D) results revealed a smaller lipid binding capacity for the T144A mutant than for the WT. In particular, the T144A mutant was unable to bind to the phosphatidylcholine lipid (POPC) bilayer. However, the addition of cholesterol (Chol) or sphingomyelin (SM) to the POPC bilayer promoted binding of the T144 mutant. Moreover, atomic force microscopy (AFM) images unveiled small aggregates of the T144A mutant on the 1:1 sphingomyelin/POPC bilayers. In contrast, the lipid binding trend for WT and T144A mutant was comparable for the 1:0.4 POPC/cholesterol and the 1:1:1 sphingomyelin/POPC/cholesterol bilayers. Furthermore, the binding of WT and T144A mutant onto erythrocyte cells was investigated. The experiments showed that the T144A mutant and the WT bind onto different areas of the erythrocyte membrane. Overall the results suggest that the T144 residue plays an important role for lipid binding. © 2020 by the authors.
Keyword
AFM | Cyt2Aa2 toxin | Erythrocyte membrane | Protein-lipid binding | QCM-D
Industrial Classification
Knowledge Taxonomy Level 1
Knowledge Taxonomy Level 2
Knowledge Taxonomy Level 3
Funding Sponsor
Austrian Science Fund; Universit?t f?r Bodenkultur Wien
License
CC BY
Rights
Author
Publication Source
Scopus