Malonate, malonyl-coenzyme A, and acetyl-coenzyme A in developing rat brain

Area of Science:

• Neurochemistry
• Developmental Biology
• Metabolic Biochemistry

Background:

• Malonate, malonyl-coenzyme A (malonyl-CoA), and acetyl-CoA are key metabolic intermediates.
• Their presence and role in the developing brain are not fully understood.

Purpose of the Study:

• To quantify free malonate, malonyl-CoA, and acetyl-CoA in rat brain during development.
• To investigate the developmental changes in these compounds.

Main Methods:

• Assay of malonate via conversion to malonyl-CoA and decarboxylation to acetyl-CoA using Pseudomonas fluorescens enzymes.
• Quantification of malonyl-CoA by conversion to acetyl-CoA using rat liver mitochondrial malonyl-CoA decarboxylase.
• Assay of acetyl-CoA using a modified CoA-cycling procedure.
• Analysis performed on rat brain tissue from embryonic day 20 to postnatal day 60.

Main Results:

• Free malonate was undetectable in prenatal brain but rose sharply postnatally, reaching 192 nmol/g at 60 days.
• Malonyl-CoA was present prenatally; adult levels were 1.83 nmol/g.
• Acetyl-CoA levels were high before birth, declining slightly with age; adult levels were 1.90 nmol/g.

Conclusions:

• Significant postnatal accumulation of free malonate occurs in the rat brain.
• The precise physiological role of free malonate in the brain remains unknown.
• Deacylation of malonyl-CoA is a potential source of free malonate in the brain.