Host defence peptide (HDP) human beta defensin 9 (HBD9)

Omar, Nazri (2016) Host defence peptide (HDP) human beta defensin 9 (HBD9). PhD thesis, University of Nottingham.

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Introduction: The emergence of antibiotic resistance has led to the continuing search for discovery of effective antibiotics. Host defence peptides (HDPs) confer defence mechanisms against infection and investigation of their specific roles and interplays are ongoing. Among the HDPs, defensins are a group of effector molecules which plays important roles in humans. Although several stereotypes of human beta defensins (hBDs) such as the hBD1-3 are well studied, other members including the human beta defensin 9 (hBD9), are not entirely known. Understanding the properties of these HDPs will enable us to discover a safe and efficacious, broad-spectrum and resistance-free antibiotic for therapeutic application in the future.

Purpose: The purpose of this study is to clone the DEFB109 gene, express and purify the hBD9 propeptide, before determining the hBD9 propeptide antimicrobial property using a recombinant system in Escherichia coli.

Methods: The second exon of the DEFB109 was amplified through reverse transcription polymerase chain reaction (RT-PCR) and inserted into selected plasmid vectors. The recombinant plasmid construct was cloned, and transformed into E coli expression host. The correctly transformed colonies were selected before the plasmid constructs were purified and verified through nucleotide sequencing. Expression and purification of the hBD9 propeptide were carried out and antimicrobial property of the peptide was investigated.

Result: HBD9 fusion protein was successfully expressed and purified. It was shown to have antimicrobial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa. The effect of the free hBD9 propeptide against wider spectrum of organisms needs to be studied in the future.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Hopkinson, A.
Dua, H.S.
Keywords: Antimicrobial peptide, Defensin, Beta defensin, Human beta defensin, Human defence peptide
Subjects: QS-QZ Preclinical sciences (NLM Classification) > QU Biochemistry
Faculties/Schools: UK Campuses > Faculty of Medicine and Health Sciences > School of Medicine
Item ID: 33280
Depositing User: Omar, Nazri
Date Deposited: 19 Jul 2016 06:40
Last Modified: 22 Dec 2017 03:38

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