AKR1B1 reduces galactose to galactitol

Stable Identifier
R-HSA-9931850
Type
Reaction [transition]
Species
Homo sapiens
Compartment
cytosol
Synonyms
alpha-D-galactose+NADPH+H+=>galactitol+NADP+
ReviewStatus
5/5
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AKR1B1 reduces galactose to galactitol
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Based on studies in mouse, ADKR1B1 catalyzes the conversion of alpha-D-galactose (a-Gal) to galactitol (Gui et al, 1995). ADKR1B1 is an NADPH-dependent aldose reductase with activity towards a variety of substrates including galactose, glucose and glyceraldehyde, among others (reviewed in Chang et al, 2018). Mouse ADKR1B1 has a lower Km for galactose than for glucose (Gui et al, 1995). Galactitol accumulates inside the cell and is thought to contribute to cataract formation in galactosemia through its hyperosmotic nature (Kinoshita et al, 1962; Dvornik et al, 1973; Lin et al, 1991). Galactitol may also contribute to galactosemia by acting as an inhibitor of GALM (galactose mutarorotase), allowing the accumulation of unmetabolized galactose (Keston, 1963; Tsakiris et al, 2002).
Literature References
PubMed ID Title Journal Year
1907924 Polyol accumulation in cultured human lens epithelial cells

Lin, LR, Reddy, VN, Giblin, FJ, Kador, PF, KINOSHITA, JH

Exp Eye Res 1991
30362099 Aldo-Keto Reductases: Multifunctional Proteins as Therapeutic Targets in Diabetes and Inflammatory Disease

Chang, KC, Petrash, JM

Adv Exp Med Biol 2018
14456181 The accumulation of dulcitol and water in rabbit lens incubated with galactose

KINOSHITA, JH, MEROLA, LO, DIKMAK, E

Biochim Biophys Acta 1962
12570032 The in vitro effects of galactose and its derivatives on rat brain Mg2+-ATPase activity

Tsakiris, S, Marinou, K, Schulpis, KH

Pharmacol Toxicol 2002
14061735 INHIBITION OF ACTION OF LENS MUTAROTASE ON GLUCOSE BY CATARACTOGENIC SUGARS AND CORRESPONDING POLYOLS

KESTON, AS

Arch Biochem Biophys 1963
4270794 Polyol accumulation in galactosemic and diabetic rats: control by an aldose reductase inhibitor

Dvornik, E, Simard-Duquesne, N, Krami, M, Sestanj, K, Gabbay, KH, KINOSHITA, JH, Varma, SD, MEROLA, LO

Science 1973
7851421 Presence of a closely related subgroup in the aldo-ketoreductase family of the mouse

Gui, T, Tanimoto, T, Kokai, Y, Nishimura, C

Eur J Biochem 1995
Participants
Input
Output
Participates
as an event of
Catalyst Activity

aldose reductase (NADPH) activity of AKR1B1 [cytosol]

Physical Entity
AKR1B1 [cytosol] (Homo sapiens)
Activity
aldose reductase (NADPH) activity (GO:0004032)
Inferred From
Akr1b1 reduces galactose to galactitol (Mus musculus)
Cross References
RHEA
Authored
Rothfels, K  (2024-12-13)
Reviewed
D'Eustachio, P  (2025-01-23)
Created
Rothfels, K  (2024-12-13)
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