Ketohexokinase (KHK) initiates fructose metabolism by catalyzing ATP-dependent phosphorylation of fructose to fructose 1-phosphate
[1]. KHK-A is produced ubiquitously at low levels, while KHK-C is highly expressed in liver, kidney, and intestine and shows greater fructose-phosphorylation activity
[1][2]. Mechanistically, KHK-C drives hepatic fructolysis, lipogenic precursor accumulation, ER stress, steatosis, and fibrogenic responses in NAFLD/NASH models
[3][4]. In disease biology, KHK-A becomes prominent in hepatocellular carcinoma cells, where it functions as a protein kinase and phosphorylates PRPS1 to promote nucleotide synthesis
[5]. Compared with KHK-C, KHK-A has lower fructokinase efficiency but distinct protein-kinase activity, making isoform selection important for experimental design
[5][6]. For experimental applications, KHK inhibitors such as PF-06835919 and LY3522348 support studies of hepatic fructose metabolism, liver exposure, and dose-dependent inhibition of fructose metabolism
[7][8].