Development of chemical tools for studying biological aldehydes: Enzyme substrates and fluorescent sensors

Because of their high reactivity, aldehydes are often recognized for their deleterious roles in the body, such as the generation of free radicals and contribution towards oxidative stress. However, these same aldehydes are also endogenously produced in the body and play vital biological roles under tightly controlled conditions. Because of this careful regulation, chemical tools for sensing aldehydes and their associated regulatory enzymes are necessary in order to learn more about their physiological roles and how their dysregulation may become pathological. In this work, we present the development of small molecule chemical tools to study aldehydes using a variety of approaches. First, we highlight our development of a fluorescent substrate for an aldehyde processing enzyme, aldehyde dehydrogenase 1A1 (ALDH1A1). ALDH1A1 belongs to a family of enzymes that process endogenous and exogenous aldehydes to carboxylic acids, detoxifying reactive aldehyde species and participating in complex signaling pathways, often related to stemness. To address the lack of isoform-selective ALDH1A1 probes, we designed a small molecule fluorescent substrate for ALDH1A1 that showed robust fluorescent turn-on only with this particular enzyme, which allowed us to use it as a tool to study the role of ALDH1A1 in cancer stem cells from a variety of cancer types, both in vitro and in vivo. Secondly, we highlight our development of a small molecule probe for formaldehyde that can detect this reactive aldehyde at endogenous levels. Our probe can detect formaldehyde in living cells and becomes highly fluorescent once concentrations become high enough to be pathological. We verified the utility of this probe in the HEK293T and Neuroscreen-1 cell lines, using both confocal microscopy and flow cytometry. In addition, we are currently developing a general small molecule aldehyde donor platform that is integrated with a fluorescent readout. The envisioned suite of tools will allow for spatiotemporal control of aldehyde release.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2020

Author dc:creator

• Anorma, Chelsea Diane

Contributors dc:contributor

• Chan, Jefferson
• Moore, Jeffrey S
• van der Donk, Wilfred A
• Olshansky, Lisa

• aldehydes, fluorescence, probes

Statement dc:rights

• Copyright 2020 Chelsea Anorma

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/108166

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/108166