Small Molecules as Alternate Substrates for 3-Methylglutaconylation.

Area of Science:

• Biochemistry
• Metabolic Disorders
• Organic Chemistry

Background:

• Leucine catabolism produces trans-3-methylglutaconyl CoA (3MGC-CoA).
• Enzyme deficiencies in HMGCL or AUH (inborn errors of metabolism) elevate 3MGC-CoA levels.
• Elevated 3MGC-CoA can non-enzymatically form 3MGC anhydride, leading to organic acid waste and protein 3MGCylation.

Purpose of the Study:

• Investigate the reactivity of 3MGC anhydride with small molecules.
• Assess the potential of small molecules to mitigate 3MGC anhydride-induced protein modification.

Main Methods:

• In vitro experiments using an anti-3MGC antibody.
• Assessing the reduction in 3MGCylated bovine serum albumin (BSA) signal intensity.
• Testing various small molecules, including amino group-containing compounds.

Main Results:

• Glycine, glucosamine, ethanolamine, and glutathione reduced 3MGCylated BSA signal intensity in a concentration-dependent manner.
• These reactive molecules contain primary amine groups.
• N-acetylglucosamine and choline did not show significant effects.

Conclusions:

• 3MGC anhydride reacts with primary amine-containing metabolites.
• This reaction acylates the primary amine groups of these metabolites.
• Potential therapeutic strategy for managing toxic metabolite buildup in specific IEMs.