Session: Current Topics in Biological Chemistry:

Our cells are continuously exposed to a slew of exogenous and endogenous electrophilic metabolites which affect cellular fitness. Methylglyoxal (MGO) is an example of such an electrophile. MGO forms adducts with nucleophilic protein residues and these resultant non-enzymatic post-translational modifications are collectively classified as advanced glycation end-products (AGEs). AGEs are an important class of protein modifications and are implicated in numerous ageing-related diseases such as neurodegeneration, diabetes, cancer, and cardiovascular disease. Thus, identifying proteins susceptible to AGE modification and understanding the functional ramifications of such protein adducts is critical in elucidating the role MGO plays in disease. Unfortunately, the chemical tools to study MGO remain limited. Often studies are performed under non-native, bolus administrations of non-physiological concentrations of MGO or MGO derivates. Additionally, the inherent reactivity of this molecule complicates analyzing cellular responses due to the plethora of potential targets. Thus, novel strategies to release MGO intracellularly are needed to better understand the cellular processes that regulate MGO and MGO modified proteins.

To address this current gap in methodology, we developed a chemical biology platform capable of releasing intracellular MGO in a controlled fashion to study proteins particularly susceptible to MGO modification. We first developed an effective photocage of MGO, enabling MGO release upon irradiation of 365-nm light with a half-life of ~10 seconds. Next, we designed and synthesized a novel probe molecule, TRMOP (targetable and releasable MGO precursor), which is capable of directing photo-releasable MGO to different subcellular locations. We then demonstrated how TRMOP can be utilized in HEK293T cells to form protein-AGEs with spatiotemporal precision. This work provides an important technology for studying the cellular responses of MGO and resultant AGEs in a controlled fashion. We hope this strategy will further illuminate the role of MGO in various disease states.

Dr Natalia Tretyakova

Professor, University of Minnesota

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