University of Illinois Urbana-Champaign

Application of a substrate-tolerant lanthipeptide synthetase in bioengineering peptide natural products

Le, Tung Thanh

Content Files
LE-DISSERTATION-2023.pdf

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https://hdl.handle.net/2142/121960

Description

Title
Application of a substrate-tolerant lanthipeptide synthetase in bioengineering peptide natural products
Author(s)
Le, Tung Thanh
Issue Date
2023-10-24
Director of Research (if dissertation) or Advisor (if thesis)
van der Donk, Wilfred A.
Doctoral Committee Chair(s)
van der Donk, Wilfred A.
Committee Member(s)
  • Silverman, Scott K.
  • Mitchell, Douglas A.
  • Zhao, Huimin
Department of Study
Chemistry
Discipline
Chemistry
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
  • lanthipeptides
  • enzymatic promiscuity
  • bio-engineering
  • RiPPs
Abstract
Lanthipeptides constitute a diverse class of peptide natural products defined by the presence of lanthionine residue(s). These peptides belong to a larger family of natural products called RiPPs, which stands for ribosomally synthesized and post-translationally modified peptides. Like many RiPPs classes, the enzymes involved in the biosynthesis of lanthipeptides demonstrate relatively high substrate tolerance, a feature which, combined with the ribosomal origin of the peptide substrates, facilitates bioengineering efforts of these peptides via evolution techniques. This dissertation is thematically built around an intriguing example of extreme catalytic promiscuity in lanthipeptides biosynthesis, the prochlorosin system. The journey starts with a discussion of why and how nature has possibly evolved the prochlorosins to favor diversity-oriented biosynthesis, followed by an overview of high-throughput screening methods that have been applied to lanthipeptides. In chapter 2, the biosynthesis of prochlorosins is shown to be under substrate control such that the site-selectivity of lanthionine formation is heavily influenced by the substrates’ primary sequences. This feature opens up an opportunity for the construction of lanthipeptide libraries which is realized in chapter 3, in which an in-liposome directed evolution experiment is described in order to discover lanthipeptides with improved bioactivity. Finally, in chapter 4, the prochlorosin biosynthetic machinery is combined with an enzyme from a distant RiPP class in order to create hybrid structures that have potentials for higher stability, affinity, or adaptability for high-throughput screening experiments.
Graduation Semester
2023-12
Type of Resource
Thesis
Handle URL
https://hdl.handle.net/2142/121960
Copyright and License Information
Copyright 2023 Tung Le

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Graduate Theses and Dissertations at Illinois