Identification of peptide substrates and development of pseudosubstrate-based peptide inhibitors for p60(C-SRC) protein tyrosine kinase

Persistent Link:
http://hdl.handle.net/10150/282230
Title:
Identification of peptide substrates and development of pseudosubstrate-based peptide inhibitors for p60(C-SRC) protein tyrosine kinase
Author:
Lou, Qiang, 1962-
Issue Date:
1996
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:
Protein tyrosine kinases (PTKs) mediate important signaling events associated with cellular growth, differentiation, and mitogenesis. The p60c-src protein is the first described cellular protein tyrosine kinase. Human p60c-src PTK has been implicated in the development of colon and breast cancer, and leukemia. However, the exact physiological role of p60c-src PTK or its physiological target proteins are not well known, and the mechanism by which the p60c-src PTK activity is regulated is not completely understood. Peptide substrates can be used to determine the substrate specificity and kinetic parameters, and therefore to provide important information for understanding of the physiological role and mechanism of action of this enzyme. Peptide substrates can also be used to develop pseudosubstrate-based peptide inhibitors for p60c-src PTK. Combinatorial peptide library methods have proven to be very powerful in identifying ligands for receptors and in discovering peptide substrates for protein kinases. In this dissertation, a "one-bead one-compound" combinatorial peptide library method was applied to identify peptide substrates for p60c-src PTK, the structure-activity relationship of the identified peptide substrates was studied, and the pseudosubstrate-based peptide inhibitors for p60c-src PTK were developed. Using the "one-bead one-compound" combinatorial peptide library method, a novel peptide, YIYGSFK, was identified as an efficient substrate for p60c-src PTK. The structure-activity relationship study was performed on over 70 analogs of YIYGSFK. It was determined that -Ile-Tyr- were the two critical residues required for activity. Based on this dipeptide motif a secondary library was synthesized (XIYXXXX, wherein X = all 19 eukaryotic amino acids except cysteine, I = isoleucine, Y = tyrosine) and screened with p60c-src PTK. One of the identified peptides, GIYWHHY, was found to be more efficient for p60c-src PTK than the parental compound, YIYGSFK. Several potent psedosubstrate based inhibitors were developed using GIYWHHY as a template. Some of the more potent inhibitors have branched structure indicating the enzyme active site can accommodate more than a linear motif. These data demonstrate that the "one-bead one-compound" combinatorial library method is a powerful tool to discover novel peptide substrates, and to develop pseudosubstrate-based peptide inhibitors for PTKs.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Chemistry, Biochemistry.; Health Sciences, Oncology.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Cancer Biology
Degree Grantor:
University of Arizona
Advisor:
Kit, S. Lam

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleIdentification of peptide substrates and development of pseudosubstrate-based peptide inhibitors for p60(C-SRC) protein tyrosine kinaseen_US
dc.creatorLou, Qiang, 1962-en_US
dc.contributor.authorLou, Qiang, 1962-en_US
dc.date.issued1996en_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.abstractProtein tyrosine kinases (PTKs) mediate important signaling events associated with cellular growth, differentiation, and mitogenesis. The p60c-src protein is the first described cellular protein tyrosine kinase. Human p60c-src PTK has been implicated in the development of colon and breast cancer, and leukemia. However, the exact physiological role of p60c-src PTK or its physiological target proteins are not well known, and the mechanism by which the p60c-src PTK activity is regulated is not completely understood. Peptide substrates can be used to determine the substrate specificity and kinetic parameters, and therefore to provide important information for understanding of the physiological role and mechanism of action of this enzyme. Peptide substrates can also be used to develop pseudosubstrate-based peptide inhibitors for p60c-src PTK. Combinatorial peptide library methods have proven to be very powerful in identifying ligands for receptors and in discovering peptide substrates for protein kinases. In this dissertation, a "one-bead one-compound" combinatorial peptide library method was applied to identify peptide substrates for p60c-src PTK, the structure-activity relationship of the identified peptide substrates was studied, and the pseudosubstrate-based peptide inhibitors for p60c-src PTK were developed. Using the "one-bead one-compound" combinatorial peptide library method, a novel peptide, YIYGSFK, was identified as an efficient substrate for p60c-src PTK. The structure-activity relationship study was performed on over 70 analogs of YIYGSFK. It was determined that -Ile-Tyr- were the two critical residues required for activity. Based on this dipeptide motif a secondary library was synthesized (XIYXXXX, wherein X = all 19 eukaryotic amino acids except cysteine, I = isoleucine, Y = tyrosine) and screened with p60c-src PTK. One of the identified peptides, GIYWHHY, was found to be more efficient for p60c-src PTK than the parental compound, YIYGSFK. Several potent psedosubstrate based inhibitors were developed using GIYWHHY as a template. Some of the more potent inhibitors have branched structure indicating the enzyme active site can accommodate more than a linear motif. These data demonstrate that the "one-bead one-compound" combinatorial library method is a powerful tool to discover novel peptide substrates, and to develop pseudosubstrate-based peptide inhibitors for PTKs.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectChemistry, Biochemistry.en_US
dc.subjectHealth Sciences, Oncology.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineCancer Biologyen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorKit, S. Lamen_US
dc.identifier.proquest9720611en_US
dc.identifier.bibrecord.b34539657en_US
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