Mannosyl-oligosaccharide 1,2-alpha-mannosidase

Mannosyl-oligosaccharide 1,2-α-mannosidase (EC 3.2.1.113, mannosidase 1A, mannosidase 1B, 1,2-α-mannosidase, exo-α-1,2-mannanase, mannose-9 processing α-mannosidase, glycoprotein processing mannosidase I, mannosidase I, Man₉-mannosidase, ManI, 1,2-α-mannosyl-oligosaccharide α-D-mannohydrolase) is an enzyme with systematic name 2-α-mannosyl-oligosaccharide α-D-mannohydrolase. It catalyses the hydrolysis of the terminal (1→2)-linked α-D-mannose residues in the oligo-mannose oligosaccharide Man₉(GlcNAc)₂.

This enzyme is involved in the synthesis of glycoproteins.

Kifunensine is a potent inhibitor of mannosidase I.

References

Tabas I, Kornfeld S (November 1979). "Purification and characterization of a rat liver Golgi α-mannosidase capable of processing asparagine-linked oligosaccharides". The Journal of Biological Chemistry. 254 (22): 11655–63. doi:10.1016/s0021-9258(19)86534-1. PMID 500665.
Tulsiani DR, Hubbard SC, Robbins PW, Touster O (April 1982). "α-D-Mannosidases of rat liver Golgi membranes: Mannosidase II is the GlcNAcMAN₅-cleaving enzyme in glycoprotein biosynthesis and mannosidases IA and IB are the enzymes converting Man₉ precursors to Man₅ intermediates". The Journal of Biological Chemistry. 257 (7): 3660–8. doi:10.1016/s0021-9258(18)34831-2. PMID 7061502.

External links

Mannosyl-oligosaccharide+1,2-alpha-mannosidase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)

Hydrolase: sugar hydrolases (EC 3.2)

3.2.1: Glycoside hydrolases

Disaccharidase	Sucrase/Sucrase-isomaltase/Invertase Maltase Trehalase Lactase
Glucosidases	Cellulase Alpha-glucosidase Acid Neutral AB Neutral C Beta-glucosidase cytosolic Debranching enzyme
Other	Amylase Alpha-amylase Chitinase Lysozyme Neuraminidase NEU1 NEU2 NEU3 NEU4 Bacterial neuraminidase Viral neuraminidase Galactosidases Alpha Beta alpha-Mannosidase Glucuronidase Klotho Hyaluronidase Pullulanase Glucosylceramidase lysosomal non-lysosomal Galactosylceramidase Alpha-N-acetylgalactosaminidase NAGA Alpha-N-acetylglucosaminidase Fucosidase Hexosaminidase HEXA HEXB Iduronidase Maltase-glucoamylase Heparanase HPSE2

3.2.2: Hydrolysing
N-Glycosyl compounds

DNA glycosylases: Oxoguanine glycosylase

v t e Enzymes
Activity	Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Diffusion-limited enzyme Cofactor Enzyme catalysis
Regulation	Allosteric regulation Cooperativity Enzyme inhibitor Enzyme activator
Classification	EC number Enzyme superfamily Enzyme family List of enzymes
Kinetics	Enzyme kinetics Eadie–Hofstee diagram Hanes–Woolf plot Lineweaver–Burk plot Michaelis–Menten kinetics
Types	EC1 Oxidoreductases (list) EC2 Transferases (list) EC3 Hydrolases (list) EC4 Lyases (list) EC5 Isomerases (list) EC6 Ligases (list) EC7 Translocases (list)

Portal:

Biology

Category:

EC 3.2.1