Title
Insights on the structure-activity relationship of peptides derived from Sticholysin II
Author
Aline Lima de Oliveira, Eduardo Maffud Cilli, Uris Ros, Edson Crusca Jr, María Eliana Lanio, Carlos Alvarez, Shirley Schreier, Thelma Aguiar Pertinhez, Alberto Spisni
Year
2018
Journal
Peptide Science
Abstract
Sticholysin II (StII) is a pore-forming actinoporin from the sea anemone Stichodactyla helianthus. A mechanistic model of its action has been proposed: proteins bind to cell membrane, insert their N-termini into the lipid core and assemble into homo-tetramer pores responsible for host-cell death. Because very likely the first 10 residues of StII N-terminus are critical for membrane penetration, to dissect the molecular details of that functionality, we studied two synthetic peptides: StII1-30 and StII16-35. They show diverse haemolytic and candidacidal activity that correlate with distinct orientations in SDS micelles. NMR shows that StII1-30 partly inserts into the micelle, while StII16-35 lays on the micelle surface. These results justify the diverse concentration dependence of their candidacidal activity supposing a different mechanism of action and providing new hints on StII lytic activity at molecular level. Biotechnological application of these peptides, focused on the development of therapeutic immunocomplexes, may be envisaged.
Instrument
J-810
Keywords
Circular dichrosim, Secondary structure, Chemical stability, Vesicle interactions, Biochemistry