Maltase-glucoamylase

Function

Alpha-(1,4) exo-glucosidase involved in breakdown of dietary starch oligosaccharides in small intestine. Cleaves the non-reducing alpha-(1,4)-linked glucose residue in linear dextrins with retention of anomeric center stereochemistry. Mainly hydrolyzes short length oligomaltoses having two to seven glucose residues. Can cleave alpha-(1,2), alpha-(1,3) and alpha-(1,6) glycosidic linkages with lower efficiency, whereas beta glycosidic linkages are usually not hydrolyzed.

Classification

Family (Pfam)

PF13802 Gal_mutarotas_2, PF01055 Glyco_hydro_31_2nd, PF21365 Glyco_hydro_31_3rd, PF00088 Trefoil

InterPro

Gal_mutarotase_sf_dom, GH, Glyco_hydro_31_AS, Glyco_hydro_31_C, Glyco_hydro_31_CS, Glyco_hydro_31_N_dom, Glyco_hydro_31_TIM, Glyco_hydro_b, P_trefoil_CS, P_trefoil_dom, P_trefoil_dom_sf

Functional cluster

Secreted Hydrolases & Toxins

Experimental structures · PDB · 12

• 2QLY X-ray 2.00A
• 2QMJ X-ray 1.90A
• 3CTT X-ray 2.10A
• 3L4T X-ray 1.90A
• 3L4U X-ray 1.90A
• 3L4V X-ray 2.10A
• 3L4W X-ray 2.00A
• 3L4X X-ray 1.90A
• 3L4Y X-ray 1.80A
• 3L4Z X-ray 2.00A
• 3TON X-ray 2.95A
• 3TOP X-ray 2.88A

A predicted model is available from AlphaFold.

Gene Ontology · 13

• GO:0016324 apical plasma membrane
• GO:0070062 extracellular exosome
• GO:0101003 ficolin-1-rich granule membrane
• GO:0005886 plasma membrane
• GO:0070821 tertiary granule membrane
• GO:0004558 alpha-1,4-glucosidase activity
• GO:0016160 amylase activity
• GO:0030246 carbohydrate binding
• GO:0003824 catalytic activity
• GO:0004574 oligo-1,6-glucosidase activity
• GO:1901027 dextrin catabolic process
• GO:0000025 maltose catabolic process
• GO:0005983 starch catabolic process

Drugs targeting this protein · 4

• MIGLITOL inhibitor
• CELGOSIVIR inhibitor
• ACARBOSE inhibitor
• VOGLIBOSE inhibitor

Related proteins · sequence + function similarity

• Sucrase-isomaltase, intestinal 0.95
• Sucrase-isomaltase, intestinal 0.95
• Sucrase-isomaltase, intestinal 0.95
• Sucrase-isomaltase, intestinal 0.95
• Probable maltase-glucoamylase 2 0.94
• Sucrase-isomaltase, intestinal 0.92
• Sucrase-isomaltase, intestinal 0.92
• Alpha-glucosidase 0.81
• Lysosomal alpha-glucosidase 0.79
• Putative alpha-xylosidase 2 0.79
• Lysosomal alpha-glucosidase 0.79
• Neutral alpha-glucosidase C 0.79

Co-cited proteins · studied together in the literature

• Sucrase-isomaltase, intestinal 1 shared papers
• Sucrase-isomaltase, intestinal 1 shared papers
• Aminopeptidase N 1 shared papers

Literature · 11 cited papers

• Contribution of the Individual Small Intestinal alpha-Glucosidases to Digestion of Unusual alpha-Linked Glycemic Disaccharides. J. Agric. Food Chem. · 2016
• Analysis of the human tissue-specific expression by genome-wide integration of transcriptomics and antibody-based proteomics. Mol. Cell. Proteomics · 2014
• Structural insight into substrate specificity of human intestinal maltase-glucoamylase. Protein Cell · 2011
• Luminal starch substrate brake on maltase-glucoamylase activity is located within the glucoamylase subunit. J. Nutr. · 2008
• Human intestinal maltase-glucoamylase: crystal structure of the N-terminal catalytic subunit and basis of inhibition and substrate specificity. J. Mol. Biol. · 2008
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). Genome Res. · 2004
• The DNA sequence of human chromosome 7. Nature · 2003
• The maltase-glucoamylase gene: common ancestry to sucrase-isomaltase with complementary starch digestion activities. Proc. Natl. Acad. Sci. U.S.A. · 2003
• Human small intestinal maltase-glucoamylase cDNA cloning. Homology to sucrase-isomaltase. J. Biol. Chem. · 1998
• Structure, biosynthesis, and glycosylation of human small intestinal maltase-glucoamylase. J. Biol. Chem. · 1988
• Tyrosine sulfation, a post-translational modification of microvillar enzymes in the small intestinal enterocyte. EMBO J. · 1987