Aldehyde dehydrogenase family 3 member A2; Catalyzes the oxidation of medium and long-chain aliphatic aldehydes to fatty acids. Active on a variety of saturated and unsaturated aliphatic aldehydes between 6 and 24 carbons in length. Responsible for conversion of the sphingosine 1- phosphate (S1P) degradation product hexadecenal to hexadecenoic acid.

Acylphosphatase-1; Its physiological role is not yet clear; Belongs to the acylphosphatase family.

Alpha-aminoadipic semialdehyde dehydrogenase; Multifunctional enzyme mediating important protective effects. Metabolizes betaine aldehyde to betaine, an important cellular osmolyte and methyl donor. Protects cells from oxidative stress by metabolizing a number of lipid peroxidation-derived aldehydes. Involved in lysine catabolism (By similarity).

Acetyl-coenzyme A thioesterase; Acyl-CoA thioesterases are a group of enzymes that catalyze the hydrolysis of acyl-CoAs to the free fatty acid and coenzyme A (CoASH), providing the potential to regulate intracellular levels of acyl-CoAs, free fatty acids and CoASH. Acyl-coenzyme A thioesterase 12/ACOT12 preferentially hydrolyzes acetyl-CoA.

4-trimethylaminobutyraldehyde dehydrogenase; Converts gamma-trimethylaminobutyraldehyde into gamma- butyrobetaine with high efficiency (in vitro). Can catalyze the irreversible oxidation of a broad range of aldehydes to the corresponding acids in an NAD-dependent reaction, but with low efficiency.

Acetyl-coenzyme A synthetase 2-like, mitochondrial; Catalyzes the synthesis of acetyl-CoA from short-chain fatty acids. Acetate is the preferred substrate. Can also utilize propionate with a much lower affinity. Provides acetyl-CoA that is utilized mainly for oxidation under ketogenic conditions. Involved in thermogenesis under ketogenic conditions, using acetate as a vital fuel when carbohydrate availability is insufficient.

Acetyl-coenzyme A synthetase, cytoplasmic; Catalyzes the synthesis of acetyl-CoA from short-chain fatty acids. Acetate is the preferred substrate but can also utilize propionate with a much lower affinity ; Belongs to the ATP-dependent AMP-binding enzyme family.

Aldehyde dehydrogenase, mitochondrial; Is capable of converting retinaldehyde to retinoic acid.

Thiopurine S-methyltransferase; Catalyzes the S-methylation of thiopurine drugs such as 6- mercaptopurine (also called mercaptopurine, 6-MP or its brand name Purinethol) using S-adenosyl-L-methionine as the methyl donor. TPMT activity modulates the cytotoxic effects of thiopurine prodrugs. A natural substrate for this enzyme has yet to be identified; Belongs to the class I-like SAM-binding methyltransferase superfamily. TPMT family.