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oai:www.ideals.illinois.edu:2142/49785 2023-07-11 col_2142_14789 col_2142_5131 com_2142_14788 com_2142_8903 com_2142_5130

Lanthionine Lanthipeptide van der Donk, Wilfred A. van der Donk, Wilfred A. Hergenrother, Paul J. Katzenellenbogen, John A. Mitchell, Douglas A. Bindman, Noah 2014-05-30T17:17:34Z 2014-05-30T17:17:34Z 2016-09-22T20:59:27Z 2014-05 2014-05-30T17:17:34Z 2014-05 Recent genome sequencing efforts have revealed that a common biosynthetic route to peptide natural products involves ribosomally synthesized and posttranslationally modified peptides (RiPPs). One of the largest classes of RiPPs is the lanthionine-containing peptides (lanthipeptides), which are characterized by intramolecular thioether crosslinks dubbed lanthionine (Lan) and methyllanthionine (MeLan). The evolvability and brevity of lanthipeptide biosynthetic pathways as well as the substrate tolerance of the biosynthetic machinery facilitates the heterologous expression of lanthipeptides and renders the ribosome-derived compounds attractive for bioengineering efforts. A major drawback to the production of lanthipeptides, either in E. coli or in vitro, is the removal of the leader peptide after posttranslational modification to generate the mature natural product. In this thesis, Chapter 2 will discuss a method to introduce a photolabile linker between lanthipeptide leader and core regions. Posttranslational modification of the lanthipeptide by its cognate synthetase in vitro, followed by UV-light mediated removal of the leader peptide, yielded the mature lanthipeptide. Chapter 3 will spotlight a novel way to engineer the ribosomal machinery to incorporate a hydroxy acid into the peptide thus generating an ester linkage directly between the lanthipeptide leader and core regions, which is selectively hydrolyzed under mild alkaline conditions. Labeling of natural products with biophysical probes has greatly contributed to investigations of their modes of action and has provided tools for visualization of their targets. However, the mode of action of only a few lantibiotics has been determined thus far. A general challenge is the availability of a suitable functional group for chemoselective modification. Chapter 4 will discuss novel methodology to introduce an N-terminal ketone into various lanthipeptides by the generation of a cryptic N-terminal dehydro amino acid by the cognate biosynthetic enzymes. Spontaneous hydrolysis of the N-terminal enamines after leader peptide removal results in α-ketoamides that site-specifically react with an aminooxy-derivatized alkyne or fluorophore. The fluorescently-modified lantibiotics were added to bacteria, and their cellular localization was visualized by confocal fluorescence microscopy as a means to determine their modes of action. Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2014-01-10T21:15:05Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Bindman_Noah.doc: 39649280 bytes, checksum: f3c6ad62241005cc3d94fee68d2accaf (MD5) Bindman_Noah.pdf: 45569856 bytes, checksum: 3de40096f6cb765faed6bfc7cc869fa1 (MD5) Made available in DSpace on 2014-05-30T17:17:34Z (GMT). No. of bitstreams: 3 Noah_Bindman.pdf: 45569856 bytes, checksum: 3de40096f6cb765faed6bfc7cc869fa1 (MD5) Bindman_Noah.doc: 39649280 bytes, checksum: f3c6ad62241005cc3d94fee68d2accaf (MD5) license.txt: 4062 bytes, checksum: c38fdb43b66b5a740031f2b93a9134c5 (MD5) Item marked as restricted to the 'Administrator' Group (id=1) by Seth Robbins (robbins.sd@gmail.com) on 2014-05-30T17:21:27Z Item is restricted until 2016-05-30T17:21:23Z Restriction data tranferred 2014-07-01T11:39:38-05:00 Original Data Group with Access Administrator Release Date: 2016-05-30 12:21:23 UTC Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Limited Restriction Lifted for Item 49836 on 2016-09-22T20:59:27Z. http://hdl.handle.net/2142/49785 en Copyright 2014 Noah Bindman peptide natural product ribosomally synthesized and posttranslationally modified peptide methyllanthionine bioengineering posttranslational modification photochemical linker lacticin 481 nukacin ISK-1 haloduracin prochlorosin nisin hydroxy acid pyrrolysyl tRNA α-ketoamide fluorescently modified lantibiotic New chemical and biosynthetic methodologies for the study of lanthipeptides text Chemistry 1413 Chemistry 0335 University of Illinois at Urbana-Champaign Dissertation Ph.D. PHD:Chemistry -UIUC 10KS0335PHD