magistrsko delo
Miki Zarić (Author), Matej Butala (Reviewer), Kristina Sepčić (Mentor), Damjana Drobne (Thesis defence commission member), Kristina Sepčić (Thesis defence commission member), Jaka Razinger (Thesis defence commission member), Matej Butala (Thesis defence commission member), Jaka Razinger (Co-mentor)

Abstract

Namen magistrske naloge je bil pridobiti egerolizinske proteine OlyA6, PlyA2 in EryA in njihov partnerski protein PlyB z domeno MACPF. Navedeni egerolizin v kompleksu s proteinom PlyB lahko tvori transmembransko neselektivno poro v membranah z ustrezno lipidno sestavo. Kombinacija EryA/PlyB je selektivno aktivna za membrane, ki vsebujejo ceramid fosfoetanolamin in holesterol, medtem ko OlyA6/PlyB in PlyA2/PlyB delujeta tudi na membrane, sestavljene iz sfingomielina in holesterola. Ker naj bi bil ceramid fosfoetanolamin, skupaj s holesterolom, prisoten v membranah določenih žuželk v dovolj visokih koncetracijah za delovanje egerolizinskih kompleksov, smo toksičnost teh testirali na plodovi vinski mušici (Drosophila suzukii), nimfah velike žitne uši (Sitobion avenae), larvah voščene vešče (Galleria mellonella) in larvah hrošča mokarja (Tenebrio molitor). Izkazalo se je, da omenjeni organizmi niso občutljivi na porotvorne komplekse, za kar je lahko odgovorna (1) odsotnost ceramid fosfoetanolamina v membranah žuželk, saj zanje ni neposredno dokazano, da ga imajo, (2) proteolitična razgradnja egerolizinskih kompleksov s črevesnimi encimi, (3) neoptimalen pH za delovanje egerolizinskih kompleksov v črevesju, (4) nedostopnost ustreznih lipidnih domen zaradi izvenceličnega matriksa ali neposrednih stereokemičnih ovir in/ali (5) odsotnost še neznanega koreceptorja, ki je v živih sistemih potreben za dokončno delovanje egerolizinskega kompleksa.

Keywords

egerolizini;OlyA6;PlyA2;EryA;PlyB;ceramid fosfoetanolamin;insekti;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [M. Zarić]
UDC: 577.1(043.2)
COBISS: 4895311 Link will open in a new window
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Downloads: 269
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Other data

Secondary language: English
Secondary title: Evaluation of toxicity of complexes of aegerolysins and macpf domain cointaining proteins against spotted wing drosophila and english grain aphid
Secondary abstract: The purpose of this master thesis was to obtain aegerolysin proteins OlyA6, PlyA2 and EryA, and their MACPF-partnering protein PlyB. Combinations of the aegerolysins with PlyB are known to form non-selective transmembrane pores on membranes of suitable lipid composition (ceramide phosphoethanolamine or spingomyelin in combination with cholesterol). EryA/PlyB is selective for combination of ceramide phosphoethanolamine and cholesterol, while OlyA6/PlyB and PlyA2/PlyB can also perforate membranes composed of sphingomyelin and cholesterol. Since ceramide phosphoethanolamine, together with cholesterol, is present in certain insect membranes in high enough concentrations for activity of aegerolysin complexes, we decided to evaluate their toxicity on spotted wing Drosophila (Drosophila suzukii), English grain aphid nymphs (Sitobion avenae), mealworm larvae (Tenebrio molitor) and greater wax moth larvae (Galleria mellonella). Results showed that none of the tested animals are susceptible to aegerolysin-based complexes. The reasons might include a (1) lack of ceramide phosphoethanolamine in membranes of these animals since there is no direct evidence of its presence in these particular insects, (2) proteolytic degradation of pore-forming proteins by gut enzymes, (3) unsuitable pH in guts for activity of aegerolysin complexes, (4) inaccessibility of appropriate lipid domains because of extracellular matrix or stereochemical obstructions or (5) absence of yet unknown coreceptor that is essential for definitive function of aegerolysins complexes in living systems.
Secondary keywords: aegerolysins;OlyA6;PlyA2;EryA;PlyB;ceramide phosphoethanolamine;insects;
Type (COBISS): Master's thesis/paper
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. Ljubljana, Biotehniška fak.
Pages: X, 54 f.
ID: 10958861