THE DESIGN AND SYNTHESIS OF NOVEL UNNATURAL AMINO ACIDS AND THE DESIGN AND SYNTHESIS OF PEPTIDES & PEPTIDOMIMETICS CONTAINING UNNATURAL AMINO ACIDS FOR THE STUDY OF G-PROTEIN COUPLED RECEPTORS

Persistent Link:
http://hdl.handle.net/10150/204274
Title:
THE DESIGN AND SYNTHESIS OF NOVEL UNNATURAL AMINO ACIDS AND THE DESIGN AND SYNTHESIS OF PEPTIDES & PEPTIDOMIMETICS CONTAINING UNNATURAL AMINO ACIDS FOR THE STUDY OF G-PROTEIN COUPLED RECEPTORS
Author:
Liu, Zhihua
Issue Date:
2010
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.
Embargo:
Embargo: Release after 6/2/2012
Abstract:
Nature has gifted peptides as important modulators in the human body, but these types of molecules often have not been favored when we were looking for therapeutic agents. The poor bioavailability, fast degradation and until recent high manufacturing costs of some bioactive peptides lowered their potential usage in the health industry. Under these circumstances, unnatural amino acids were developed as indispensible tools providing enormous support to peptide science. By incorporating proper unnatural amino acids into a peptide or protein, we now can significantly improve peptide's or protein's half-life, cell permeability, bio-distribution, etc. In addition, their potency and receptor/acceptor selectivity could also be enhanced. Site-specific modifications of peptides and proteins under physiological conditions with the use of unnatural amino acids also have been made easier with the advance of biotechnology. Therefore, my research described in this dissertation contributes to the efforts in the development of novel unnatural amino acids. In particular, I have focused on novel methods in the synthesis of anti beta-functionalized gamma,delta-unsaturated amino acids. These amino acids have special interests in peptide chemistry: they can provide conformational constraints to the peptide 3D structures; the beta-functionalization allows the introduction of pharmaceutically interesting side chain groups; and the terminal double bond which is orthogonal to peptide synthesis provides access to further chemical modifications. Two general methodologies for the synthesis of both racemic and optically active anti beta-functionalized gamma,delta--unsaturated amino acids were developed by using the thio-Claisen rearrangement (TCR) reaction. Excellent diastereoselectivies and enantioselectivities were obtained when C2-symmetric chiral auxiliaries were selected to control the stereochemistry outcome. The mechanism and the scope of the TCR reaction were also studied, showing unique advantages in the preparation of these biological interesting amino acids.Another effort of developing angiotensin II type 1 (AT1) receptor biased peptide ligands is also documented in this dissertation. The AT1 receptor is a 7-transmembrane G-protein coupled receptor, which recent researches have shown could be activated through a beta-arrestins only, but G-protein independent, pathway. We synthesized 12 analogs of Sar1,Ile4,Ile8-AngII (SII), and tested them in biological assays, and obtained valuable information for further "perfect" biased ligands design.
Type:
text; Electronic Dissertation
Keywords:
Amino Acid; Asymmetric Synthesis; Peptide; Peptidomimetic
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Chemistry
Degree Grantor:
University of Arizona
Advisor:
Hruby, Victor J.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleTHE DESIGN AND SYNTHESIS OF NOVEL UNNATURAL AMINO ACIDS AND THE DESIGN AND SYNTHESIS OF PEPTIDES & PEPTIDOMIMETICS CONTAINING UNNATURAL AMINO ACIDS FOR THE STUDY OF G-PROTEIN COUPLED RECEPTORSen_US
dc.creatorLiu, Zhihuaen_US
dc.contributor.authorLiu, Zhihuaen_US
dc.date.issued2010-
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.releaseEmbargo: Release after 6/2/2012en_US
dc.description.abstractNature has gifted peptides as important modulators in the human body, but these types of molecules often have not been favored when we were looking for therapeutic agents. The poor bioavailability, fast degradation and until recent high manufacturing costs of some bioactive peptides lowered their potential usage in the health industry. Under these circumstances, unnatural amino acids were developed as indispensible tools providing enormous support to peptide science. By incorporating proper unnatural amino acids into a peptide or protein, we now can significantly improve peptide's or protein's half-life, cell permeability, bio-distribution, etc. In addition, their potency and receptor/acceptor selectivity could also be enhanced. Site-specific modifications of peptides and proteins under physiological conditions with the use of unnatural amino acids also have been made easier with the advance of biotechnology. Therefore, my research described in this dissertation contributes to the efforts in the development of novel unnatural amino acids. In particular, I have focused on novel methods in the synthesis of anti beta-functionalized gamma,delta-unsaturated amino acids. These amino acids have special interests in peptide chemistry: they can provide conformational constraints to the peptide 3D structures; the beta-functionalization allows the introduction of pharmaceutically interesting side chain groups; and the terminal double bond which is orthogonal to peptide synthesis provides access to further chemical modifications. Two general methodologies for the synthesis of both racemic and optically active anti beta-functionalized gamma,delta--unsaturated amino acids were developed by using the thio-Claisen rearrangement (TCR) reaction. Excellent diastereoselectivies and enantioselectivities were obtained when C2-symmetric chiral auxiliaries were selected to control the stereochemistry outcome. The mechanism and the scope of the TCR reaction were also studied, showing unique advantages in the preparation of these biological interesting amino acids.Another effort of developing angiotensin II type 1 (AT1) receptor biased peptide ligands is also documented in this dissertation. The AT1 receptor is a 7-transmembrane G-protein coupled receptor, which recent researches have shown could be activated through a beta-arrestins only, but G-protein independent, pathway. We synthesized 12 analogs of Sar1,Ile4,Ile8-AngII (SII), and tested them in biological assays, and obtained valuable information for further "perfect" biased ligands design.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectAmino Aciden_US
dc.subjectAsymmetric Synthesisen_US
dc.subjectPeptideen_US
dc.subjectPeptidomimeticen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorHruby, Victor J.en_US
dc.contributor.committeememberMash, Eugene A.en_US
dc.contributor.committeememberPyun, Jefferyen_US
dc.contributor.committeememberZheng, Zhipingen_US
dc.identifier.proquest10913-
dc.identifier.oclc659754808-
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.