Literature summary for 3.2.1.48 extracted from

Sim, L.; Willemsma, C.; Mohan, S.; Naim, H.Y.; Pinto, B.M.; Rose, D.R.
Structural basis for substrate selectivity in human maltase-glucoamylase and sucrase-isomaltase N-terminal domains (2010), J. Biol. Chem., 285, 17763-17770.

Crystallization (Commentary)

Crystallization (Comment)	Organism
free enzyme and enzyme in complex with the inhibitor kotalanol, hanging drop vapor diffusion method, 0.001 ml of reservoir solution containing 0.5 M NaCl, 0.1 M bis tris propane, pH 7.0, and 18% PEG 4000, is equilibrated over 0.0015 ml of protein solution and 0.003 ml of reservoir solution, containing 0.1 M MgCl2, 0.1 M bis tris propane, pH 7.0, 15% PEG 4000, X-ray diffraction structure determination and analysis at 3.2 and 2.15 A resolution, respectively, molecular replacement	Homo sapiens

Crystallization (Comment)

Organism

free enzyme and enzyme in complex with the inhibitor kotalanol, hanging drop vapor diffusion method, 0.001 ml of reservoir solution containing 0.5 M NaCl, 0.1 M bis tris propane, pH 7.0, and 18% PEG 4000, is equilibrated over 0.0015 ml of protein solution and 0.003 ml of reservoir solution, containing 0.1 M MgCl2, 0.1 M bis tris propane, pH 7.0, 15% PEG 4000, X-ray diffraction structure determination and analysis at 3.2 and 2.15 A resolution, respectively, molecular replacement

Homo sapiens

Inhibitors

Inhibitors	Comment	Organism	Structure
acarbose	binding structure,overview	Homo sapiens
kotalanol	binding structure, strong structural conservation of -1 subsite residues, overview	Homo sapiens

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism
1.3	-	4-nitrophenyl-alpha-D-glucoside	pH 6.5, 37°C	Homo sapiens
7.1	-	maltose	pH 6.5, 37°C	Homo sapiens
11.1	-	isomaltose	pH 6.5, 37°C	Homo sapiens

Localization

Localization	Comment	Organism	GeneOntology No.	Textmining
brush border membrane	-	Homo sapiens	31526	-

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
additional information	Homo sapiens	hydrolyze the mixture of linear alpha-1,4- and branched alpha-1,6-oligosaccharide substrates that typically make up terminal starch digestion products	?	-	?
sucrose + H2O	Homo sapiens	-	alpha-D-glucose + D-fructose	-	?

Organism

Organism	UniProt	Comment	Textmining
Homo sapiens	P14410	cf. EC 3.2.1.10	-

Source Tissue

Source Tissue	Comment	Organism	Textmining
small intestine	-	Homo sapiens	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.
4-nitrophenyl-alpha-D-glucoside + H2O	-	Homo sapiens	4-nitrophenol + alpha-D-glucose	-	?
isomaltose + H2O	-	Homo sapiens	2 alpha-D-glucose	-	?
maltose + H2O	-	Homo sapiens	alpha-D-glucose + D-glucose	-	?
additional information	hydrolyze the mixture of linear alpha-1,4- and branched alpha-1,6-oligosaccharide substrates that typically make up terminal starch digestion products	Homo sapiens	?	-	?
additional information	human maltase-glucoamylase and sucrase-isomaltase are composed of duplicated catalytic domains, N- and C-terminal, which display overlapping substrate specificities. The N-terminal catalytic domain of human MGAM has a preference for short linear alpha-1,4-oligosaccharides, whereas N-terminal SI has a broader specificity for both alpha-1,4- and alpha-1,6-oligosaccharides	Homo sapiens	?	-	?
sucrose + H2O	-	Homo sapiens	alpha-D-glucose + D-fructose	-	?

Subunits

Subunits	Comment	Organism
More	human maltase-glucoamylase and sucrase-isomaltase are composed of duplicated catalytic domains, N- and C-terminal, which display overlapping substrate specificities	Homo sapiens

Synonyms

Synonyms	Comment	Organism
sucrase-isomaltase	-	Homo sapiens

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
37	-	assay at	Homo sapiens

Turnover Number [1/s]

Turnover Number Minimum [1/s]	Turnover Number Maximum [1/s]	Substrate	Comment	Organism
17	-	4-nitrophenyl-alpha-D-glucoside	pH 6.5, 37°C	Homo sapiens
97	-	isomaltose	pH 6.5, 37°C	Homo sapiens
137	-	maltose	pH 6.5, 37°C	Homo sapiens

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
6.5	-	assay at	Homo sapiens

Ki Value [mM]

Ki Value [mM]	Ki Value maximum [mM]	Inhibitor	Comment	Organism	Structure
0.0006	-	kotalanol	pH 6.5, 37°C	Homo sapiens
0.014	-	acarbose	pH 6.5, 37°C	Homo sapiens