Use this URL to cite or link to this record in EThOS:
Title: Control of peptide secondary structure : photomodulation of peptide helicity in the apoptosis signalling pathway
Author: Taylor, Nicholas John
ISNI:       0000 0001 2422 2298
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2008
Availability of Full Text:
Access from EThOS:
Access from Institution:
Short peptides have been designed and synthesised based on the JV-terminus of the p53 tumour suppressor. The crosslinking of these peptides with a thiol-reactive azobenzene crosslinker, optimised for water solubility, builds on previous research that has demonstrated the effective use of this chemical crosslinker in the regulation of a helical peptide structure. Both the crosslinked and uncrosslinked peptides were reported to bind Hdm-2 with high affinity when compared to the wild-type peptide and the isomeric conformation of the attached crosslinker was reported to influence Hdm-2 binding. Although the extent of binding affinity change through crosslinker conformational switching was not as high as intended, this low degree of structural control contributed to the hypothesis that the strength of the peptide interactions with Hdm-2 is enough to overcome the conformational constraints imposed by the crosslinker and that the extent of secondary structure change upon photoswitching may be enhanced by engineering peptides to bind Hdm-2 though with a reduced affinity. The synthesis of Hdm-2 mutants designed to possess a reduced affinity for p53 further supported this proposal. The design of Hdm-2 binding peptides based on a polyalanine scaffold was explored, since polyalanine forms a stable a-helix. The substitution of alanine residues in the appropriate positions respective to one-another with key p53 residues critical to Hdm-2 binding in addition to cysteine residues to enable the attachment of the azobenzene crosslinker led to the development of peptides with Hdm-2 binding affinities comparable to wild-type p53.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available