isomerase

Term: isomerase

Literally meaning: “separating isomers”

Origin: Anc Greek

/éσος/isos(=equal)

+μέρος/meros(=part)

-άση/-asy(=-ase) suffix added to the name of the substrate that the enzyme  hydrolyzes eg proteinase for protein or lipase for lipids

>διά-/dia-(=prefix denoting “through”, “apart” )

> δυο/dio(two) + στάσις/stasis(=halt) > ίστημι/histimi(=stand).

Coined/History

The isomerism was first noticed in 1827, when Friedrich Woehler prepared cyanic acid and noted that although its elemental composition was identical to fulminic acid its properties were different. The term “isomerism” coined in 1830, by Swedish chemist Jons Jacob Berzelius(1779-1848)  who wrote “those bodies that have the same composition but different properties”. Louis Pasteur (1822-1895) in 1848 separated racemic acid into its two optically active tartaric acid components by crystallization. The first documented occurrence of isomerase was shown by Meyerhof and Kiessling (1935) for reaction: Glyceraldehyde phosphate to dihydroxyacetone phosphate.

Sources

1. J.J. Berzelius (1831) “Über die Zusammensetzung der Weinsäure und Traubensäure (John's säure aus den Voghesen), über das Atomengewicht des Bleioxyds, nebst allgemeinen Bemerkungen über solche Körper, die gleiche Zusammensetzung, aber ungleiche Eigenschaften besitzen," Annalen der Physik und Chemie, vol. 19, pages 305–335;

2. MEYERHOF, 0. 1935 tVber die Kinetick der umkehrbaren Reaktion zwischen Hexosediphosphorsaure und Dioxyacetonphosphorsaure. Biochem. Z.,277: 77-96.

Definition

Isomerases are the enzymes that catalyze the structural rearrangement of isomers (molecules with mirror-image relation) such as isomerase that converts L-alanine to D-alanine or the Glucose-6-phosphate isomerase that converts glucose-6-phosphate in the second step of glycolysis. They have the EC classification as EC 5.