Biophysical characterisation of LL-37-derived antimicrobial peptides

master's thesis

• Title (croatian): Biofizikalna karakterizacija antimikrobnih peptida izvedenih iz LL-37
• Author: Drago Ilišinović
• Mentor: Gordana Maravić Vlahoviček (mentor)
• Committee member: Sandra Šupraha Goreta (predsjednik povjerenstva)
• Committee member: Lidija Bach-Rojecky (član povjerenstva)
• Committee member: Mario Jug (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of biochemistry and molecular biology); Zagreb
• Defense date and country: 2016-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Pharmacy

Abstract

Antimicrobial peptides (AMPs) are a novel class of therapeutics with activity against bacteria. Such peptides mostly act by disrupting bacterial cytoplasmic membrane. Therefore, membrane composition as well as peptide properties are both important in determining a peptide’s level of activity. Such peptides may have both positive and negative additional properties. Therefore, new peptides with better and enhanced properties are being developed. One of such peptides is OP-145, derived from LL-37. From OP-145, new AMPs were developed, including P148 and P276, which were researched in this thesis. OP-145, P148 and P276 were subjected to a series of test which included in silico modelling and investigation of their interactions with prokaryotic and eukaryotic model membranes by terms of thermoanalytical measurements using DSC, measurements of size of model membrane vesicles in interaction with peptides using DLS, determination of peptides’ secondary structure in interaction with membranes using CD and quantitative research of the peptides’ ability to disrupt these membranes in the form of leakage assays using fluorometry. Data gained from these experiments was then compared to previously known properties of the peptides. Results have shown a stronger level of activity of P148 and P276 in comparison to OP-145 towards both bacterial and mammalian model membranes. It was concluded that P148 and P276 have better biophysical properties than OP-145 in terms of antimicrobial activity, but that further research is needed in order to better understand their properties and possible therapeutic use.

Abstract (croatian)

Antimikrobni peptidi (AMP) su nova klasa terapeutika s antibakterijskom aktivnošću. Način djelovanja tih peptida je većinom narušavanje integriteta stanične membrane. Stoga su i sastav membrane i svojstva peptida važni za utvrđivanje stupnja aktivnosti peptida. Takvi peptidi mogu imati i dodatna svojstva, pozitivna i negativna. Stoga se razvijaju novi peptidi s poboljšanim svojstvima. Jedan od takvih peptida je i OP-145 koji je razvijen iz LL-37. Iz OP-145 su razvijeni novi antimikrobni peptidi, uključujući P148 i P276 koji su istraživani u ovom radu. OP-145, P148 i P276 su podvrgnuti nizu ispitivanja uključujući in silico modeliranje i istraživanje njihovih interakcija s prokariotskim i eukariotskim modelnim membranama koristeći termoanalitičke metode (DSC), mjerenje veličina vezikula modelnih membrana koristeći DLS, određivanje sekundarne strukture peptida u interakciji s modelnim membranama koristeći CD i određivanje stupnja aktivnosti prema membranama mjereći curenje fluorescentnog sadržaja iz vezikula. Dobiveni podaci su uspoređeni s otprije poznatim svojstvima tih peptida. Rezultati su pokazali povećan stupanj aktivnosti P148 i P276 u usporedbi s OP-145 prema prokariotskim i eukariotskim modelnim membranama. Zaključeno je da P148 i P276 imaju bolja biofizikalna svojstva od OP-145 u smislu antimikrobne aktivnosti, ali i da su potrebna daljnja istraživanja tih peptida kako bi se bolje utvrdila njihova svojstva i mogućnost primjene.

• Keywords: antimicrobial peptides; model membranes; LL-37; OP-145; P148; P276
• Keywords (croatian): antimikrobni peptidi; modelne membrane; LL-37; OP-145; P148; P276
• Language: english
• URN:NBN: urn:nbn:hr:163:963331
• Study programme: Title: Pharmacy; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra farmacije (magistar/magistra farmacije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2016-12-02 16:04:25