Isomaltulose synthase

In enzymology, an isomaltulose synthase (EC 5.4.99.11) is an enzyme that catalyzes the chemical reaction

sucrose ${\displaystyle \rightleftharpoons }$ 6-O-Alpha-D-Glucopyranosyl-D-Fructofuranose

isomaltulose synthase
Identifiers
EC no.	5.4.99.11
CAS no.	159940-49-5
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

Hence, this enzyme has one substrate, sucrose (table sugar), and one product, 6-O-Alpha-D-Glucopyranosyl-D-Fructofuranose (also known as isomaltulose or Palatinose). It converts the α-1,2 glycosidic linkage between glucose and fructose in sucrose into the α-1,6 glycosidic linkage between glucose and fructose in isomaltulose.

This enzyme belongs to the family of isomerases. The systematic name of this enzyme class is sucrose glucosylmutase. Other names in common use include sucrose isomerase, sucrose alpha-glucosyltransferase, and trehalulose synthase.

The isomaltulose synthase of the bacterium Protaminobacter rubrum is commonly used in the industrial production of isomaltulose.^[1]

Structural studies

As of late 2007, 7 structures have been solved for this class of enzymes, with PDB accession codes 1M53, 1ZJA, 1ZJB, 2PWD, 2PWE, 2PWF, and 2PWG.