Multivalent Interactions Based on Supramolecular Self-Assembly and Peptide-Labeled Quantum Dots for Imaging GPCRs

Persistent Link:
http://hdl.handle.net/10150/195308
Title:
Multivalent Interactions Based on Supramolecular Self-Assembly and Peptide-Labeled Quantum Dots for Imaging GPCRs
Author:
Zhou, Min
Issue Date:
2006
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Multivalent interactions are common in nature, such as influenza virus infecting epithelial cells, clearance of pathogens by antibody-mediated attachment to macrophages, etc. To mimic nature, we utilized a bottom-up approach to develop various multivalent self-assembling systems based on leucine-zipper peptides. We tethered several pairs of leucine-zipper peptides to PAMAM dendrimers to form leucine-zipper dendrimers (LZDs). We conjugated Fos/Jun to the dendrimer to make D0Fos4 and D0Jun4, and studied the interactions between these LZDs and their cognate peptide target, either Jun or Fos. Our experiments showed that the D0Fos4 can non-covalently assemble four copies of Jun, and this approach can be further used for the rapid non-covalently assembling of multimeric ligands. We also pursued the multivalent target of GPCRs with a Fos/Jun assembly, and found the complex can potentially be used as a molecular switch to target GPCRs with controlled ligand activity. In a related project for bio-material design based on self-assembly of LZDs, we synthesized a different pair of LZDs, D-Ez4 and D-Kz4, and established that they can assemble at neutral pH to form helical fibrils which display higher order self-organized structures, providing a new methodology for bio-material design. In another effort for studying multivalent interactions, we conjugated three copies of the F23, mini-protein that binds the HIV-1 capsid protein, to a trimesic acid and obtained a trivalent inhibitor, Tri-F23. Tri-F23 showed enhanced binding in ELISA against gp120, but was not significantly more effective preventing HIV entry. This methodology provides a new strategy for developing multivalent inhibitors for preventing HIV-1 infection at the entry level. In a related area, we are developing imaging agents based on quantum dots that can detect GPCRs on whole cells and at the single molecule level. To this end, a new method was developed for biocompatible amphphilic polymers to coat quantum dots. This amphiphilic polymer facilitates rapid quantum dot conjugation to any ligand with a free thiol or engineered cysteine. Several GPCR targeted peptides have been utilized for imaging receptors on whole cells and as single molecules. These efforts will guide the rational design of multivalent ligands for targeting GPCRs and other cell surface proteins.
Type:
text; Electronic Dissertation
Keywords:
Multivalent interaction; Coiled-coil; Self-assembling; HIV-1; Quantum dots; GPCR
Degree Name:
PhD
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Ghosh, Indraneel
Committee Chair:
Ghosh, Indraneel

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleMultivalent Interactions Based on Supramolecular Self-Assembly and Peptide-Labeled Quantum Dots for Imaging GPCRsen_US
dc.creatorZhou, Minen_US
dc.contributor.authorZhou, Minen_US
dc.date.issued2006en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractMultivalent interactions are common in nature, such as influenza virus infecting epithelial cells, clearance of pathogens by antibody-mediated attachment to macrophages, etc. To mimic nature, we utilized a bottom-up approach to develop various multivalent self-assembling systems based on leucine-zipper peptides. We tethered several pairs of leucine-zipper peptides to PAMAM dendrimers to form leucine-zipper dendrimers (LZDs). We conjugated Fos/Jun to the dendrimer to make D0Fos4 and D0Jun4, and studied the interactions between these LZDs and their cognate peptide target, either Jun or Fos. Our experiments showed that the D0Fos4 can non-covalently assemble four copies of Jun, and this approach can be further used for the rapid non-covalently assembling of multimeric ligands. We also pursued the multivalent target of GPCRs with a Fos/Jun assembly, and found the complex can potentially be used as a molecular switch to target GPCRs with controlled ligand activity. In a related project for bio-material design based on self-assembly of LZDs, we synthesized a different pair of LZDs, D-Ez4 and D-Kz4, and established that they can assemble at neutral pH to form helical fibrils which display higher order self-organized structures, providing a new methodology for bio-material design. In another effort for studying multivalent interactions, we conjugated three copies of the F23, mini-protein that binds the HIV-1 capsid protein, to a trimesic acid and obtained a trivalent inhibitor, Tri-F23. Tri-F23 showed enhanced binding in ELISA against gp120, but was not significantly more effective preventing HIV entry. This methodology provides a new strategy for developing multivalent inhibitors for preventing HIV-1 infection at the entry level. In a related area, we are developing imaging agents based on quantum dots that can detect GPCRs on whole cells and at the single molecule level. To this end, a new method was developed for biocompatible amphphilic polymers to coat quantum dots. This amphiphilic polymer facilitates rapid quantum dot conjugation to any ligand with a free thiol or engineered cysteine. Several GPCR targeted peptides have been utilized for imaging receptors on whole cells and as single molecules. These efforts will guide the rational design of multivalent ligands for targeting GPCRs and other cell surface proteins.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectMultivalent interactionen_US
dc.subjectCoiled-coilen_US
dc.subjectSelf-assemblingen_US
dc.subjectHIV-1en_US
dc.subjectQuantum dotsen_US
dc.subjectGPCRen_US
thesis.degree.namePhDen_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorGhosh, Indraneelen_US
dc.contributor.chairGhosh, Indraneelen_US
dc.contributor.committeememberHruby, Victor J.en_US
dc.contributor.committeememberOlenyuk, Bogdan Z.en_US
dc.contributor.committeememberSaavedra, S. Scotten_US
dc.contributor.committeememberMontfort, William R.en_US
dc.identifier.proquest1844en_US
dc.identifier.oclc659746390en_US
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