Hepatic fructokinase
| ketohexokinase (fructokinase) | |||||||
|---|---|---|---|---|---|---|---|
Ketohexokinase homodimer, Human | |||||||
| Identifiers | |||||||
| Symbol | KHK | ||||||
| NCBI gene | 3795 | ||||||
| HGNC | 6315 | ||||||
| OMIM | 229800 | ||||||
| RefSeq | NM_006488 | ||||||
| UniProt | P50053 | ||||||
| Other data | |||||||
| EC number | 2.7.1.3 | ||||||
| Locus | Chr. 2 p23.3-23.2 | ||||||
| |||||||
| Ketohexokinase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 2.7.1.3 | ||||||||
| CAS no. | 9030-50-6 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
Hepatic fructokinase (or ketohexokinase) is an enzyme that catalyzes the phosphorylation of fructose to produce fructose-1-phosphate.
Isoforms
In humans, ketohexokinase is encoded by the KHK gene, which produces two isoforms, KHK-A and KHK-C, through alternative splicing.
- KHK-C is primarily expressed in the liver, kidney, and intestine. It has a high affinity for fructose (low Km) and is responsible for the majority of fructose metabolism.
- KHK-A is ubiquitously expressed in many tissues at low levels. It has a significantly lower affinity for fructose (high Km) compared to the C isoform.[2]
References
- ^ Bais R, James HM, Rofe AM, Conyers RA (1985). "The purification and properties of human liver ketohexokinase. A role for ketohexokinase and fructose-bisphosphate aldolase in the metabolic production of oxalate from xylitol". Biochem. J. 230 (1): 53–60. doi:10.1042/bj2300053. PMC 1152585. PMID 2996495.
- ^ Diggle CP, Shires M, Leitch D, Brooke D, Carr IM, Markham AF, Hayward BE, Asipu A, Bonthron DT (2009). "Ketohexokinase: Expression and Localization of the Principal Fructose-metabolizing Enzyme". Journal of Histochemistry & Cytochemistry. 57 (8): 763–774. doi:10.1369/jhc.2009.953190. PMC 2713076. PMID 19365088.
External links
- Hepatic+fructokinase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)