Galactokinase 1 (GALK1)

Galactokinase 1 (GALK1) is an ATP-dependent enzyme that catalyzes the phosphorylation of α-D-galactose to galactose 1-phosphate, representing the essential committed step in galactose catabolism via the Leloir pathway[8][3][4][5]. This enzyme allows the body to convert galactose, derived primarily from lactose in the diet, into glucose and other biomolecules that serve as energy sources or structural constituents[3][1]. Human galactokinase 1 is a member of the GHMP kinase superfamily, featuring a two-domain structure with a conserved nucleotide-binding motif[2][8]. Genetic defects in GALK1 lead to type II galactosemia (galactokinase deficiency), which is characterized by cataracts due to the toxic accumulation of galactose and galactitol, particularly in the lens of the eye, without the broader systemic issues seen in classic galactosemia[1][5]. More than 30 distinct mutations have been identified in individuals with this metabolic disorder[1]. No direct pharmacological inhibitors or modulators are available; clinical management relies on dietary galactose restriction[3].

Other names

galactokinaseATP:D-galactose 1-phosphotransferaseGK1GALKGALK1_HUMAN[3][1][8]

Not applicable for direct drugs; for enzyme replacement or gene therapy, mechanism would be restoration of enzyme activity