isomaltose + H2O => 2 D-glucose (sucrase-isomaltase)

Stable Identifier
Reaction [transition]
Homo sapiens
SI (sucrase-isomaltase) hydrolyzes isomaltose to yield glucose
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The alpha-1,6 linkages of extracellular isomaltose are hydrolyzed to yield glucose in a reaction catalyzed by sucrase-maltase (Sim et al. 2010). In the body, this enzyme is found as a dimer on the external face of enterocytes in microvilli of the small intestine (Hauri et al. 1985). The predominant form of mature SI in the membrane is a dimer, as established from a variety of studies of the processing of the porcine enzyme (Cowell et al. 1986; Danielsen 1994) and crystallographic studies of the human one (Sim et al. 2010).
Literature References
PubMed ID Title Journal Year
20356844 Structural basis for substrate selectivity in human maltase-glucoamylase and sucrase-isomaltase N-terminal domains

Rose, DR, Sim, L, Pinto, BM, Willemsma, C, Mohan, S, Naim, HY

J. Biol. Chem. 2010
3897250 Expression and intracellular transport of microvillus membrane hydrolases in human intestinal epithelial cells

Hauri, HP, Fransen, JA, Bienz, D, Marxer, A, Sterchi, EE

J Cell Biol 1985
7906143 Dimeric assembly of enterocyte brush border enzymes

Danielsen, EM

Biochemistry 1994
3800897 Topology and quaternary structure of pro-sucrase/isomaltase and final-form sucrase/isomaltase

Tranum-Jensen, J, Cowell, GM, Sjöström, H, Norén, O

Biochem J 1986
Catalyst Activity

alpha-1,4-glucosidase activity of sucrase-isomaltase dimer [plasma membrane]

Orthologous Events
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