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Synthesis and Screening of Peptide Libraries for Biological Applications

Trinh, Thi Ba
http://rave.ohiolink.edu/etdc/view?acc_num=osu1405520102

Abstract Details

2014, Doctor of Philosophy, Ohio State University, Chemistry.
Combinatorial chemistry is a powerful tool in medicinal chemistry as well as chemical biology. In this work, we have applied combinatorial chemistry toward the analysis of peptide cyclization, specificity profiling of protein kinases and the identification of novel inhibitors against medicinally important protein targets. We have developed a high-throughput screening method to comprehensively evaluate the on-resin cyclization efficiency of peptides with regard to ring size, sequence composition and reaction condition. Several combinatorial peptide libraries were synthesized on solid-phase with varying number of random positions. Utilizing a biotin-based screening method, we were able to select fast and slow cyclizing peptides and sequence them using partial Edman degradation/mass spectrometry (PED/MS). The results have provided a truly global profile for on-resin peptide cyclization efficiency. Applying combinatorial chemistry toward chemical biology, we have developed a robust method for the profiling of protein kinases for their substrate specificity. Several peptide libraries containing 3-5 random amino acids flanking a phosphorylatable residue (Ser, Thr and Tyr) were synthesized on solid-phase. Upon treatment of the libraries with kinase of interest and an ATP analog, we were able to selectively label the phosphorylated peptides with a fluorescent probe. Sequencing of selected peptide substrates by the PED/MS method provided the specificity profile of several kinases. The screening results led to the identification of a novel protein substrate. In a related application toward chemical biology, we generated a chimeric protein kinase bearing a foreign SH2 domain to evaluate the contribution of the SH2 domain to the overall substrate specificity of a kinase. Utilizing the same screening and sequencing method for kinase specificity profiling, we were able to profile the substrate specificity of the chimeric kinase. The specificity profile was indeed remarkably different from that of the wild type kinase. In our final work, we applied combinatorial chemistry toward the identification of novel, cell-permeable inhibitors of medicinally important protein targets, such as K-Ras and phosphatases. Combinatorial peptidomimetic libraries bearing a small-molecule “warhead” were synthesized on solid phase. Screening of the peptide libraries against K-Ras produced potent binders may serve as attractive leads for further development into anticancer agents.
Dehua Pei (Advisor)
Jovica Badjic (Committee Member)
Jennifer Ottesen (Committee Member)
180 p.
Chemistry
Combinatorial library, peptide cyclization, kinase profiling

Recommended Citations

Citations

  • Trinh, T. B. (2014). Synthesis and Screening of Peptide Libraries for Biological Applications [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1405520102

    APA Style (7th edition)

  • Trinh, Thi. Synthesis and Screening of Peptide Libraries for Biological Applications. 2014. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1405520102.

    MLA Style (8th edition)

  • Trinh, Thi. "Synthesis and Screening of Peptide Libraries for Biological Applications." Doctoral dissertation, Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1405520102

    Chicago Manual of Style (17th edition)

osu1405520102
527
© 2014, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.