Single-chain nanoparticle based catalysts

Chen, Junfeng

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https://hdl.handle.net/2142/108117 Copy

Description

Title

Single-chain nanoparticle based catalysts

Author(s)

Chen, Junfeng

Issue Date

2020-04-23

Director of Research (if dissertation) or Advisor (if thesis)

Zimmerman, Steven C

Doctoral Committee Chair(s)

Zimmerman, Steven C

Committee Member(s)

• Cheng, Jianjun
• Lu, Yi
• Murphy, Catherine J

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Single-Chain Nanoparticle, catalyst, click chemistry, crosslinking

Abstract

Enzymes achieve their excellent catalytic properties by surrounding the catalytic sites with a polypeptide scaffold. The three-dimensional structure of the peptide chains creates a local environment that supramolecularly binds substrates to facilitate the catalysis. In this dissertation, synthetic polymers are used to serve a similar role, binding substrates and creating an optimal environment for performing efficient catalysis. Several single-chain nanoparticle (SCNP) catalysts have been developed to perform copper(I)-mediated alkyne–azide cycloaddition (CuAAC), “click” reactions, or the photoreduction of azido groups to amines. The nanoparticles are shown to have significantly higher activity when compared to analogous small molecule catalysts. Structure-activity relationships and reaction mechanisms are studied with SCNPs of different structures. The polymeric scaffolds are found to bind substrates in an enzyme-like manner. The catalysts operate in two modes: an “uptake mode” where small molecule substrates bind inside the polymer pockets and an “attach mode” that involves surface binding of protein substrates. The versatility and high efficiency of the nanoparticles lead to applications in protein and cell surface modification. In addition, another SCNP was shown to co-deliver an exogenous enzyme inside cells. The enzyme and SCNP reside and stay active in the endosomes, in essence engineering the endosome into an artificial organelle. The SCNP-enzyme complex can perform both concurrent and tandem reactions performing organic synthesis intracellularly. The combination of SCNP and enzymatic catalysts provides a versatile tool for intracellular organic synthesis with applications in chemical biology.

Graduation Semester

2020-05

Type of Resource

Thesis

Permalink

http://hdl.handle.net/2142/108117

Copyright and License Information

Chapter 1 Copyright 2020 ACS, Chapter 2 Copyright 2018 ACS, Chapter 3 Copyright 2019 ACS, Chapter 4 Copyright 2020 ACS

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