Projects / Programmes
Specificity of interaction of some cytolytic proteins with membrane lipid domains
Code |
Science |
Field |
Subfield |
1.05.00 |
Natural sciences and mathematics |
Biochemistry and molecular biology |
|
Code |
Science |
Field |
P310 |
Natural sciences and mathematics |
Proteins, enzymology |
P340 |
Natural sciences and mathematics |
Lipids, steroids, membranes |
Cytolytic protein; pore-forming protein; lipid membrane; lipid domain; liposome; lipid monolayer; lipid bilayer; unilamellar vesicle; toxin; SPR; EPR; epifluorescence microscopy.
Researchers (14)
no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publications |
1. |
15686 |
PhD Gregor Anderluh |
Biochemistry and molecular biology |
Researcher |
2004 - 2007 |
935 |
2. |
27539 |
PhD Biserka Bakrač Bremec |
Biochemistry and molecular biology |
Junior researcher |
2006 - 2007 |
29 |
3. |
21407 |
PhD Sabina Berne |
Biotechnology |
Researcher |
2004 |
157 |
4. |
23477 |
PhD Mojca Beseničar |
Biochemistry and molecular biology |
Junior researcher |
2004 - 2007 |
40 |
5. |
22470 |
PhD Katarina Črnigoj Kristan |
Biochemistry and molecular biology |
Junior researcher |
2004 - 2005 |
35 |
6. |
06994 |
PhD Peter Maček |
Biochemistry and molecular biology |
Principal Researcher |
2004 - 2007 |
524 |
7. |
12001 |
PhD Janja Majhenc |
Physics |
Technician |
2004 - 2007 |
73 |
8. |
17422 |
Irena Pavešič |
|
Technician |
2004 - 2007 |
1 |
9. |
27541 |
PhD Andrej Razpotnik |
Natural sciences and mathematics |
Junior researcher |
2006 - 2007 |
18 |
10. |
24291 |
PhD Katja Rebolj |
Neurobiology |
Junior researcher |
2004 - 2007 |
56 |
11. |
12278 |
PhD Maja Rupnik |
Microbiology and immunology |
Researcher |
2004 - 2007 |
643 |
12. |
15328 |
PhD Kristina Sepčić |
Biochemistry and molecular biology |
Researcher |
2004 - 2007 |
698 |
13. |
01119 |
PhD Marjeta Šentjurc |
Biochemistry and molecular biology |
Mentor to junior researcher |
2004 - 2007 |
512 |
14. |
06905 |
PhD Tom Turk |
Biochemistry and molecular biology |
Researcher |
2004 - 2007 |
602 |
Organisations (3)
Abstract
Binding and pore-formation by cytolytic proteins equinatoxin II (EqtII), a representative of actinoporins, and ostreolysin (Oly) from oyster mushroom, a representative of the aegerolysin protein family, have been shown to be dependant on specific lipid composition of the targeted membrane. There is evidence that EqtII binds and oligomerizes in sphingomyelin containing lipid membranes while preliminary data on the Oly lipid preference reveals specificity for both sphingomyelin and cholesterol. As both lipids are well known to contribute to formation of specific membrane lipid domains, such as lipid rafts, we shall study the proteins binding and pore-forming activity on lipid monolayers, small, large and giant unilamellar lipid vesicles (SUV, LUV, GUV) with respect to occurrence of the specific lipid domains in the model membranes. In comparison, a heteronemertine cytolysin, parborlysin, and bee venom melittin will be used as lipid-nonspecific pore-forming polypeptides. A cytotoxin from the pathogenic bacterium Clostridium difficile, showing lipid.binding and pore-forming activity, will also be analysed for lipid specificity. Lipid domains in SUV and LUV will be detected and characterized by analysis of the line-shape of the electron raramagnetic resonance (EPR) spectra of spin-labelled vesicles, which will give information on order parameter and ratio of diffrent domains in the membrane. Fluorescent lipid probes will be used to visualize specific lipid domains in monolayers and GUV made of binary or ternary lipid mixtures (sphingomyelin, cholesterol, palmitoyl-oleyl-phosphatidylcholine,POPC, or dipalmitoyl-phosphatidyl-choline, DOPC). Alternatively, recombinant EqtII and Oly will be designed to attach fluorescent labels by the thiol chemistry. After binding of the labelled cytolysins, either active or with depressed pore-forming activity, to monolayers and GUV their lateral distribution will be visualized with epifluorescence microscopy and correlated to lipid domain patches reported by domain-specific fluorescent lipid probes (monolayers and GUV). In addition, GUV shapes will be analyzed with respect to the labeled lipid domains and the proteins lateral distribution on the membrane. Based on the fact that either sphingomyelin and cholesterol preferentially distribute into the liquid ordered lipid phase the study is also aimed at developing a fluorescently labeled EqtII and Oly as probes sensing liquid ordered domains in artificial and biological membranes.