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Title: Identification and molecular cloning of bioactive peptides from the skin secretions of Bombina toad species
Author: Bai, Bing
ISNI:       0000 0004 2740 8436
Awarding Body: Queen's University Belfast
Current Institution: Queen's University Belfast
Date of Award: 2012
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Amphibians possess a unique defence mechanism to protect themselves against predators in their natural environment. The dermal granular glands of amphibians synthesise and expel an extraordinarily-rich variety of biologically-active peptides with potential as therapeutic leads. Because of this, scientists have been studying the novel bioactive peptides in amphibian skin secretions and attempting to transform them into drugs for clinical use. From Bombina toads, a great number of peptides with biological activities have been isolated and characterised. In this thesis, we describe a new technique that employed frozen trifluoroacetic acid (TF A)-solvated skin secretions of Bombina variegata to perform parallel peptidome and transcriptome analyses. Robust cDNA libararies were successfully constructed from this material and from such we cloned the biosynthetic precursor-encoding cDNAs of one known bombesin and three novel bombesin-Iike peptides which displayed potent effects on mammalian smooth muscle preparations. Subsequently, eleven different cDNAs encoding the biosynthetic precursors of 19 bombinin-like antimicrobial peptides were successfully cloned. From the original TF A-solvated skin secretion, we isolated two peptides that represent the prototypes of a new structural class of antimicrobial peptides from the skin secretions Bombina toads. Following the discovery of multiple novel bombinin-like peptides, we selected one, Bombinin H-BV1, for a systematic screen of possible anti-cancer activity against a panel of 11 different human tumor cell lines. This peptide displayed a most potent activity against a wide range of employed cancer cell lines.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available