Identification, molecular cloning and modification of skin-derived bioactive peptides from selected Hylidae and Ranidae
type: CreativeWork
description: Amphibians produced a series of adaptations to combat predators and various pathogenic microorganisms in their habitats. One of the greatest adaptations was the peptides secreted from the skin, which are of great importance to maintain their everyday life. Diverse bioactivities and potential pharmaceutical functions of peptides have been confirmed by researchers in recent years. Many peptides show antimicrobial activity to different extents and are less prone to induce bacterial resistance. However, during the evaluation of therapeutic potential, the unfavorable factors of peptides were revealed like modest MIC values relative to conventional antibiotics, higher costs of synthesis/production, stability against proteases, etc. Therefore, a series of approaches have been exploited to design peptide derivatives with improved qualities. Modification based on adjusting the hydrophobicity and hydrophobic moment and ultra-short peptide design are fast and effective means to increase the bioactivity of peptides. Besides, the applications of other approaches, like alanine scanning, W-tagging, unnatural amino acid replacement, introduction of chemical groups, etc., also have achieved great success. Here, different transformation methods were also suggested to generate ideas for future work in Chapter 6. In this thesis, the analysis of peptides was focused on selected species from Hylidae and Ranidae. With the completion and development of gene sequencing, identification of single peptides from complex mixtures is achievable. In this thesis, the primary structures of peptides, PS-PH, QUB-2492 and QUB-3383, were determined from the skin secretions of Phyllomedusa hypochondrialis, Phyllomedusa baltea and Hylarana guentheri, through ‘shotgun’ cloning. In parallel to this strategy, predicted mature peptides were identified and isolated from skin secretion using HPLC and structures verified by LC-MS. The peptides were then chemically-synthesised to produce the quantities required f…
abstract: Amphibians produced a series of adaptations to combat predators and various pathogenic microorganisms in their habitats. One of the greatest adaptations was the peptides secreted from the skin, which are of great importance to maintain their everyday life. Diverse bioactivities and potential pharmaceutical functions of peptides have been confirmed by researchers in recent years. Many peptides show antimicrobial activity to different extents and are less prone to induce bacterial resistance. However, during the evaluation of therapeutic potential, the unfavorable factors of peptides were revealed like modest MIC values relative to conventional antibiotics, higher costs of synthesis/production, stability against proteases, etc. Therefore, a series of approaches have been exploited to design peptide derivatives with improved qualities. Modification based on adjusting the hydrophobicity and hydrophobic moment and ultra-short peptide design are fast and effective means to increase the bioactivity of peptides. Besides, the applications of other approaches, like alanine scanning, W-tagging, unnatural amino acid replacement, introduction of chemical groups, etc., also have achieved great success. Here, different transformation methods were also suggested to generate ideas for future work in Chapter 6. In this thesis, the analysis of peptides was focused on selected species from Hylidae and Ranidae. With the completion and development of gene sequencing, identification of single peptides from complex mixtures is achievable. In this thesis, the primary structures of peptides, PS-PH, QUB-2492 and QUB-3383, were determined from the skin secretions of Phyllomedusa hypochondrialis, Phyllomedusa baltea and Hylarana guentheri, through ‘shotgun’ cloning. In parallel to this strategy, predicted mature peptides were identified and isolated from skin secretion using HPLC and structures verified by LC-MS. The peptides were then chemically-synthesised to produce the quantities required f…
author: Chen, Guanzhu
language: eng
date published: 2019-12
date modified: 2026-07-24T03:55:05Z
provider: Queen's University Belfast
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Queen's University Belfast