CoA

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Coenzyme A is a coenzyme. It is worth noting its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the tricarboxylic acid cycle. All enzymes encoded by the genome sequencing date use coenzyme A as a substrate and use (or thioesters, such as acetyl-CoA) as a substrate in about 4% of cellular enzymes. In humans, coenzyme A biosynthesis requires cysteine, pantothenic acid, and adenosine triphosphate (ATP). Mainly involved in the metabolism of fatty acids and pyruvate.

Figure 1. Structure of Coenzyme A.

Functions

• Provide body energy

Coenzyme A is a cofactor for more than 70 kinds of enzyme reaction pathways in the body, including the decomposition of carbohydrates, the oxidation of fatty acids, the decomposition of amino acids, and the degradation of pyruvate, which stimulate the tricarboxylic acid cycle and provide 90% of the energy required for the body's life.

• Provide active substances

Coenzyme A is involved in the synthesis of a large number of essential substances in the body. Synthesize neuromuscular messenger and neurotransmitter acetylcholine and melatonin (melatonin) which promote sleep in the brain. Neuromuscular messengers can exchange information between nerves and muscles, and neurotransmitters can transmit information about emotions, external stimuli, memory, and learning between nerves and the brain.

• Acyl transfer

Coenzyme A is an important acetyl and acyl transmitter.

• Activate immune function

Coenzyme A supports the body's immune system to detoxify harmful substances, activate white blood cells, promote the synthesis of hemoglobin, and participate in the synthesis of antibodies.

• Promote connective tissue formation and repair

Coenzyme A can promote the synthesis of connective tissue components of chondroitin sulfate and hyaluronic acid, and plays an important role in the formation, protection and repair of cartilage.

• Other effects

Coenzyme A promotes the utilization of Coenzyme Q10 and Coenzyme I, and reduces the side effects caused by antibiotics and other drugs.

Pharmacological action

Coenzyme A is extracted from fresh yeast. It is the coenzyme for the acetylation reaction in the body. It can be combined with acetate to form acetyl-Coenzyme A. It enters the oxidation process and plays an important role in the metabolism of sugar, protein and fat; the tricarboxylic acid cycle in the body. The synthesis of acetylcholine, the storage of liver glycogen, the reduction of cholesterol and the regulation of plasma fat content are all closely related to coenzyme A. However, some people currently believe that pantothenic acid, the main component of Coenzyme A, is not lacking in the human body. Generally, patients do not need to supplement Coenzyme A. Exogenous Coenzyme A is a macromolecule and cannot easily enter the cell through the cell membrane, so its efficacy is questionable.

Applications

Coenzyme A can be obtained from various chemical suppliers in the form of free acid and lithium or sodium salt. The free acid of Coenzyme A is unstable. It degrades by about 5% after 6 months of storage at -20°C, and is almost completely degraded after 1 month of storage at 37°C. The lithium and sodium salts of CoA are more stable, and under different temperatures, the degradation within a few months is almost negligible. The aqueous solution of Coenzyme A is unstable when the pH is higher than 8. After 24 hours at 25°C and pH 8, it loses 31% of its activity. The CoA stock solution is relatively stable when frozen at pH 2-6. The main way for the loss of CoA activity may be the air oxidation of CoA to CoA disulfide. CoA mixed disulfides, such as CoA-S-S-glutathione, are common contaminants in the commercial preparation of CoA. Free CoA can be regenerated from CoA disulfide, or it can be mixed with CoA disulfide and a reducing agent (such as dithiothreitol or 2-mercaptoethanol).