Translocation of cell-penetrating peptides across biological membranes and interactions with plasma membrane constituents
Failid
Kuupäev
2016-07-05
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
Raku plasmamembraan ümbritseb ja kaitseb rakku ning on bioloogilistele molekulidele selektiivselt läbilaskev, olles ka barjääriks paljudele potentsiaalsetele terapeutilise toimega makromolekulidele. Enamik bioaktiivseid ühendeid on suure molekulmassiga ja hüdrofiilsed ning seetõttu on takistatud nende rakkudesse pääsemine ja kasutamine meditsiinis. Et suurendada bioaktiivsete molekulide rakkudesse pääsemist, on kasutusele võetud erinevad transportsüsteemid. Ühed perspektiivsemad transportvektorid on rakku sisenevad peptiidid (RSP), mis on võimelised läbima bioloogilisi membraane ning transportima erinevaid bioaktiivseid ühendeid rakkudesse. RSP-de efektiivseks kasutamiseks biotehnoloogias ja meditsiinis on oluline mõista nende peptiidide membraani läbimise mehhanisme. Arvukad uuringud on näidanud, et RSP-d liiguvad rakkudesse erinevaid endotsütoosiradu kasutades või läbivad rakku ümbritseva membraani translokatsiooni teel. Samas ei ole siiski seniajani üheselt selge, kuidas RSP-de translokatsioon täpselt aset leiab ning millised interaktsioonid RSP-de ja raku pinna erinevate komponentide vahel sisenemist soodustavad. Seetõttu oli käesoleva töö põhieesmärgiks uurida, millised membraani koostisosad mõjutavad RSP-de rakkudesse sisenemist. Doktoritöö tulemused annavad ülevaate mitmete membraani komponentide, nagu valgud ja polüsahhariidid, rollist RSP-de translokatsioonis ning selgitab millistest membraani mikrodomeenidest sisenemine eelistatult aset leiab.
The usage of a broad range of bioactive molecules, such as nucleic acid and protein drugs with intracellular activity, is hampered by their poor plasma membrane permeability. To overcome this major bottleneck various cellular delivery systems have been developed. One class of very promising delivery tools is cell-penetrating peptides (CPPs), short amino acid sequences that are capable of efficient cellular transport of various bioactive macromolecules. The mechanisms and pathways of cellular entry of CPPs have been intensely studied in last two decades, and while it is widely acknowledged that these peptides internalize using different modes of endocytosis, the second internalization route – direct translocation through the plasma- or endosomal membrane, has remained elusive so far. Furthermore, despite the extensive research, the understanding of the exact role of specific cell surface molecules mediating the direct translocation of CPPs across membranes is still controversial. The detailed identification of the molecular interactions with the plasma membrane constituents and more detailed knowledge about the exact internalization mechanism of CPPs would enable the design and efficient usage of these cellular delivery vehicles. Thus, the main purpose of this thesis was to pinpoint the specific binding partners of CPPs on the cell surface, and the membrane dynamics that enable direct translocation through the cellular membranes. The results of the study demonstrate the role of different cell surface constituents, such as proteins and polysaccharides, that are required for the direct translocation of CPPs across membranes and the lipid components of the membrane that allow efficient cellular entry of CPPs.
The usage of a broad range of bioactive molecules, such as nucleic acid and protein drugs with intracellular activity, is hampered by their poor plasma membrane permeability. To overcome this major bottleneck various cellular delivery systems have been developed. One class of very promising delivery tools is cell-penetrating peptides (CPPs), short amino acid sequences that are capable of efficient cellular transport of various bioactive macromolecules. The mechanisms and pathways of cellular entry of CPPs have been intensely studied in last two decades, and while it is widely acknowledged that these peptides internalize using different modes of endocytosis, the second internalization route – direct translocation through the plasma- or endosomal membrane, has remained elusive so far. Furthermore, despite the extensive research, the understanding of the exact role of specific cell surface molecules mediating the direct translocation of CPPs across membranes is still controversial. The detailed identification of the molecular interactions with the plasma membrane constituents and more detailed knowledge about the exact internalization mechanism of CPPs would enable the design and efficient usage of these cellular delivery vehicles. Thus, the main purpose of this thesis was to pinpoint the specific binding partners of CPPs on the cell surface, and the membrane dynamics that enable direct translocation through the cellular membranes. The results of the study demonstrate the role of different cell surface constituents, such as proteins and polysaccharides, that are required for the direct translocation of CPPs across membranes and the lipid components of the membrane that allow efficient cellular entry of CPPs.
Kirjeldus
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Märksõnad
rakud, peptiidid, membraanid, cells (biology), peptides, membranes