Sentient macromolecules – proteins – comprise the labor force of cells. The mercurial among them are enzymes, which catalyze chemical reactions to accelerate manufacture of bioproducts.
Many proteins endeavor as a group effort. For enzymes, teamwork is essential for prompt production.
“The “metabolon” was proposed in 1985 to be a complex of metabolite-catalyzing enzymes that channel metabolites from one enzyme to the next, thus limiting their diffusion,” explained molecular biologist Theodore Alexandrov. “Enzymes are not haphazardly located throughout cells, but instead occur in discrete clusters, or metabolons, that carry out specific metabolic pathways,” concluded American biochemist Stephen Benkovic.
Enzymes set up production lines – pathways which channel molecules – to fabricate specific compounds, or, conversely, to break down bioproducts to reap energy and specific substrates. These metabolic factories are commonly associated with mitochondria, which act as the power plants for eukaryotic cells.
“The efficiency of biosynthetic pathways is increased by channeling,” explained Benkovic. “Enzymes act synergistically to increase pathway flux.”
References:
Vidhi Pareek et al, “Metabolomics and mass spectrometry imaging reveal channeled de novo purine synthesis in cell,” Science (17 April 2020).
Theodore Alexandrov, “Probing metabolism in time and space,” Science (17 April 2020).
Sara Lajeunesse, “Study finds evidence for existence of elusive ‘metabolon’,” Phys.org (16 April 2020).