Enzymes are usually named in two ways: customary naming and systematic naming.

Customary naming

Usually based on two principles:

1. The substrate of enzymes, such as amylase;

2. The type of catalytic reaction, such as dehydrogenase.

There are also names that are based on the above two principles or add other characteristics of the enzyme, such as succinate dehydrogenase, alkaline phosphatase, etc.

Conventional naming is simpler and has been used for a long time, but it lacks systematization and is not very reasonable, which has caused confusion in the names of some enzymes. For example, enterokinase and myokinase, from the literal meaning, look like two enzymes with different sources but similar functions, but in fact their modes of action are completely different. Another example: copper thiolase and acetyl-CoA transacylase are actually the same enzyme, but the names are completely different.

In view of the above situation and the increasing number of newly discovered enzymes, in order to adapt to the new development of enzymology, the Enzyme Committee of the International Biochemical Association recommended a set of systematic enzyme naming schemes and classification methods, and decided that each enzyme should have a systematic name and a customary name. At the same time, each enzyme has a fixed number.

System naming

The systematic nomenclature of enzymes is based on the overall reaction catalyzed by the enzyme.

For example, a trypsin numbered "3.4.21.4"

The first number “3” indicates hydrolase;

The second number “4” indicates that it is a protease that hydrolyzes peptide bonds;

The third number "21" indicates that it is a serine protease with an important serine residue at the active site;

The fourth number "4" indicates that it is the fourth enzyme identified in this type.

The regulations stipulate that the name of each enzyme should clearly state the name of the substrate and its catalytic properties. If there are two substrates in the enzyme reaction, both substrates must be listed, separated by ":".

For example: When alanine aminotransferase (customary name) is written as a systematic name, its two substrates "L-alanine" and "α-ketoglutarate" should be listed at the same time. The nature of the reaction it catalyzes is transamination, which also needs to be specified, so its name is "L-alanine: α-ketoglutarate aminotransferase".

Since system names are generally very long and inconvenient to use, customary names can be used in descriptions.

Enzyme products are the product of fermentation of sugar and fruit, that is, a mixture of "fruit pickles" and "low-alcohol sweet fruit wine". For example, a low-alcohol fruit wine made from fully fermented (non-soaked) green plums.