Artificial mitochondria. The way this was achieved was first by growing a type of vesicle, which is basically a spherical capsule, called an exosome, which is for containing signaling molecules for intracellular communication. There's a whole series of steps involving the exosomes and verifying things were working as intended with fluorescent molecules explained in the article, which I'm going to skip but you should read if you want to understand the mechanics. I'm going to jump to the part about mitochondria.
"Armed with this knowledge, the team sought to create functional artificial mitochondria that are capable of producing energy inside the cells. To achieve this, ATP synthase and bo3 oxidase were reconstituted into the earlier exosomes containing GOx and HRP, respectively. These exosomes were in turn fused to create nanoreactors that can produce ATP using glucose and dithiothreitol (DTT). It was found that the fused exosomes were capable of penetrating deep into the core part of a solid spheroid tissue and produce ATP in its hypoxic environment. The activities of these simple organelles were accompanied by marked reduction of reactive oxygen species (ROS) generation. In contrast, free enzymes were unable to penetrate inside these tightly packed spheroids of cells."
ATP synthase is an enzyme that takes adenosine diphosphate (ADP) and pops on a phosphate to make adenosine triphosphate (ATP), the energy molecule that all the food you eat eventually gets translated into and that drives all the actual activity in the cell. As for bo3 oxidase, I can't really tell you what that is, other than that it is something called a "quinol oxidase". An oxidase is an enzyme that takes an electron off an atom (for some unknown reason removing an electron is called "oxidation" in chemistry). Quinol oxidases catalyze the movement of electrons from quinol to oxygen to turn the oxygen into water. Quinol is a derivative of benzene with chemical formula C6H4(OH)2. It's not a molecule that naturally occurs in your cells, or any other species for that matter. It's produced either from benzene and propene or phenol.
"ATP synthase was reconstituted into CEx-GOx and bo3 oxidase was reconstituted into CEx-HRP. The two CEx were fused and were able to penetrate deep into spheroids."
"CEx" is catechol, "GOx" is glucose oxidase, and "HRP" is horseradish peroxidase.
Catechol is a molecule with a benzene core and two hydroxy groups (functional groups with the chemical formula ending in -OH) and is actually toxic to humans. Glucose oxidase is an enzyme that does an oxidation reaction (that means removing an electron, remember) with glucose to produce hydrogen peroxide and something called GDL (D-glucono-delta-lactone). It's not a human enzyme -- it's found in fungi. The enzyme horseradish peroxidase isn't a human enzyme, either. You'll never guess where it comes from. The roots of horseradish.
At this point I can't tell you how this all comes together to form a functioning mitochondria and the paper is paywalled, so I guess this is the end of the road. Seems like an impressive and unexpected accomplishment, although "artificial mitochondria" suggests it could replace the mitochondria in your cells, and it certainly can't do that as far as I can tell. It doesn't do the electron transport chain or anything that your actual mitochondria do; it produces ATP by a completely different mechanism and is probably nowhere near as efficient as the mitochondria in your cells. Better keep your mitochondria in good shape so you won't need artificial replacements.
Scientists explore the creation of artificial organelles
#discoveries #biology #organicchemistry #organelles #exosomes #mitochondria
