Defective SI does not hydrolyze maltotriose

Stable Identifier
R-HSA-5659899
Type
Reaction [transition]
Species
Homo sapiens
Compartment
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Mutations that disrupt the catalytic activity or strongly interfere with proper folding, glycosylation and transport of SI (sucrase-isomaltase) are inferred to block the cleavage of maltotriose to maltose and glucose, based on the experimentally demonstrated failure of these SI mutant proteins to hydrolyze maltose (e.g., Sander et al. 2005) and the broad substrate specificity of the normal enzyme (Sim et al. 2010).

Literature References
PubMed ID Title Journal Year
16329100 Novel mutations in the human sucrase-isomaltase gene (SI) that cause congenital carbohydrate malabsorption

Sander, P, Alfalah, M, Keiser, M, Korponay-Szabo, I, Kovács, JB, Leeb, T, Naim, HY

Hum. Mutat. 2006
20356844 Structural basis for substrate selectivity in human maltase-glucoamylase and sucrase-isomaltase N-terminal domains

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

J. Biol. Chem. 2010
Participants
Participant Of
Catalyst Activity
Catalyst Activity
Title
alpha-1,4-glucosidase activity of SI mutant dimers [plasma membrane]
Physical Entity
Activity
Normal reaction
Inferred From
Disease
Name Identifier Synonyms
intestinal disaccharidase deficiency 9868
Authored
Reviewed
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