Biophysical studies of peptides with functions in biotechnology and biology
My thesis concerns spectroscopic studies (NMR, CD and fluorescence) of peptides with functions in biotechnology and biology, and their interactions with a model membrane (large unilamellar phospholipid vesicles). The resorufin-based arsenical hairpin binder (ReAsH) bound to a short peptide is a usef...
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Stockholms universitet, Institutionen för biokemi och biofysik
2012
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ndltd-UPSALLA1-oai-DiVA.org-su-669482013-04-09T16:41:26ZBiophysical studies of peptides with functions in biotechnology and biologyengMadani, FatemehStockholms universitet, Institutionen för biokemi och biofysikStockholm : Department of Biochemistry and Biophysics, Stockholm University2012Genetic fluorescence labelBiarsenical tetracysteine motifCell-penetrating peptidesLarge unilamellar vesiclesPyrenebutyrateEndosomal escapeMembrane perturbationBacteriorhodopsinDynorphinMy thesis concerns spectroscopic studies (NMR, CD and fluorescence) of peptides with functions in biotechnology and biology, and their interactions with a model membrane (large unilamellar phospholipid vesicles). The resorufin-based arsenical hairpin binder (ReAsH) bound to a short peptide is a useful fluorescent tag for genetic labeling of proteins in living cells. A hairpin structure with some resemblance to type II β-turn was determined by NMR structure calculations (Paper I). Cell-penetrating peptides (CPPs) are short (30-35 residues), often rich in basic amino acids such as Arg. They can pass through the cell membrane and deliver bioactive cargoes, making them useful for biotechnical and pharmacological applications. The mechanisms of cellular uptake and membrane translocation are under debate. Understanding the mechanistic aspects of CPPs is the major focus of Papers II, III, and IV. The effect of the pyrenebutyrate (PB) on the cellular uptake, membrane translocation and perturbation of several CPPs from different subgroups was investigated (Paper II). We concluded that both charge and hydrophobicity of the CPP affect the cellular uptake and membrane translocation efficiency. Endosomal escape is a crucial challenge for the CPP applications. We modeled the endosome and endosomal escape for different CPPs to investigate the corresponding molecular mechanisms (Papers III and IV). Hydrophobic CPPs were able to translocate across the model membrane in the presence of a pH gradient, produced by bacteriorhodopsin proton pumping, whereas a smaller effect was observed for hydrophilic CPPs. Dynorphin A (Dyn A) peptide mutations are associated with neurodegenerative disorders, without involvement of the opioid receptors. The non-opioid activities of Dyn A may involve membrane perturbations. Model membrane-perturbations by three Dyn A mutants were investigated (Paper V). The results showed effects to different degrees largely in accordance with their neurotoxic effects. <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.</p>Doctoral thesis, comprehensive summaryinfo:eu-repo/semantics/doctoralThesistexthttp://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-66948urn:isbn:978-91-7447-417-6application/pdfinfo:eu-repo/semantics/openAccess |
collection |
NDLTD |
language |
English |
format |
Doctoral Thesis |
sources |
NDLTD |
topic |
Genetic fluorescence label Biarsenical tetracysteine motif Cell-penetrating peptides Large unilamellar vesicles Pyrenebutyrate Endosomal escape Membrane perturbation Bacteriorhodopsin Dynorphin |
spellingShingle |
Genetic fluorescence label Biarsenical tetracysteine motif Cell-penetrating peptides Large unilamellar vesicles Pyrenebutyrate Endosomal escape Membrane perturbation Bacteriorhodopsin Dynorphin Madani, Fatemeh Biophysical studies of peptides with functions in biotechnology and biology |
description |
My thesis concerns spectroscopic studies (NMR, CD and fluorescence) of peptides with functions in biotechnology and biology, and their interactions with a model membrane (large unilamellar phospholipid vesicles). The resorufin-based arsenical hairpin binder (ReAsH) bound to a short peptide is a useful fluorescent tag for genetic labeling of proteins in living cells. A hairpin structure with some resemblance to type II β-turn was determined by NMR structure calculations (Paper I). Cell-penetrating peptides (CPPs) are short (30-35 residues), often rich in basic amino acids such as Arg. They can pass through the cell membrane and deliver bioactive cargoes, making them useful for biotechnical and pharmacological applications. The mechanisms of cellular uptake and membrane translocation are under debate. Understanding the mechanistic aspects of CPPs is the major focus of Papers II, III, and IV. The effect of the pyrenebutyrate (PB) on the cellular uptake, membrane translocation and perturbation of several CPPs from different subgroups was investigated (Paper II). We concluded that both charge and hydrophobicity of the CPP affect the cellular uptake and membrane translocation efficiency. Endosomal escape is a crucial challenge for the CPP applications. We modeled the endosome and endosomal escape for different CPPs to investigate the corresponding molecular mechanisms (Papers III and IV). Hydrophobic CPPs were able to translocate across the model membrane in the presence of a pH gradient, produced by bacteriorhodopsin proton pumping, whereas a smaller effect was observed for hydrophilic CPPs. Dynorphin A (Dyn A) peptide mutations are associated with neurodegenerative disorders, without involvement of the opioid receptors. The non-opioid activities of Dyn A may involve membrane perturbations. Model membrane-perturbations by three Dyn A mutants were investigated (Paper V). The results showed effects to different degrees largely in accordance with their neurotoxic effects. === <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Manuscript.</p> |
author |
Madani, Fatemeh |
author_facet |
Madani, Fatemeh |
author_sort |
Madani, Fatemeh |
title |
Biophysical studies of peptides with functions in biotechnology and biology |
title_short |
Biophysical studies of peptides with functions in biotechnology and biology |
title_full |
Biophysical studies of peptides with functions in biotechnology and biology |
title_fullStr |
Biophysical studies of peptides with functions in biotechnology and biology |
title_full_unstemmed |
Biophysical studies of peptides with functions in biotechnology and biology |
title_sort |
biophysical studies of peptides with functions in biotechnology and biology |
publisher |
Stockholms universitet, Institutionen för biokemi och biofysik |
publishDate |
2012 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-66948 http://nbn-resolving.de/urn:isbn:978-91-7447-417-6 |
work_keys_str_mv |
AT madanifatemeh biophysicalstudiesofpeptideswithfunctionsinbiotechnologyandbiology |
_version_ |
1716579988501692416 |