Sorbitol dehydrogenase

Basic Information
Short Name	Sord, SDH, L-iditol 2-dehydrogenase
UNP ID	P27867
Organism	Rattus norvegicus
Cys Site	Cys45, Cys130
Family/Domain	Zinc-binding dehydrogenase, Zinc-containing alcohol dehydrogenase family
Known Ligand	Ligand list
Function Type	Metabolic enzyme

Summary

Protein Function

Sorbitol dehydrogenase is an enzyme include in carbohydrate metabolism converting sorbitol, the sugar alcohol form of glucose, into fructose. Together with aldose reductase, it provides a way for the body to produce fructose from glucose without using ATP.
Sorbitol dehydrogenase uses NAD⁺ as a cofactor; its reaction is:

Sorbitol + NAD⁺ --> fructose + NADH + H⁺.

A zinc ion is also involved in catalysis. Organs that use it most frequently include the liver and seminal vesicle; it is found in all kinds of organisms from bacteria to humans. A secondary use is the metabolism of dietary sorbitol, though sorbitol is known not to be absorbed as well in the intestine as its related compounds glucose and fructose, and is usually found in quite small amounts in the diet (except when used as an artificial sweetener). (From Wikipedia)
Converts sorbitol to fructose. Part of the polyol pathway that plays an important role in sperm physiology. May play a role in the sperm motility by providing an energetic source for sperm. (From Uniprot)

Cys Function & Property

Cys45 is the metal binding site of Sord. And two regions, residues 90–110 and 120–140, are very important for the stability and binding between subunits in mammalian SDHs. (PMID: 22752181, 17952367)

• Hydrophobic property:

• SASA：

Cys45: Unknown

Cys120: Unknown

Protein Sequence

MAAPAKGENL SLVVHGPGDI RLENYPIPEL GPNDVLLKMH SVGICGSDVH
YWEHGRIGDF VVKKPMVLGH EAAGTVTKVG PMVKHLKPGD RVAIEPGVPR
EIDEFCKIGR YNLTPSIFFC ATPPDDGNLC RFYKHSADFC YKLPDSVTFE
EGALIEPLSV GIYACRRGSV SLGNKVLVCG AGPIGIVTLL VAKAMGASQV
VVIDLSASRL AKAKEVGADF TIQVAKETPH DIAKKVESVL GSKPEVTIEC
TGAESSVQTG IYATHSGGTL VVVGMGPEMI NLPLVHAAVR EVDIKGVFRY
CNTWPMAVSM LASKTLNVKP LVTHRFPLEK AVEAFETAKK GLGLKVMIKC
DPNDQNP

Structural Information

• Known structure with covalent ligand:
  

Unknown

• Protein structure:

Unknown

Related Pathway

• Pentose and glucuronate interconversions
  
• Fructose and mannose metabolism
  
• Metabolic pathways
  

Experimental Evidence

MALDI-TOF/MS, Cys Modification Assay

Reference

1. Kanda H, Toyama T, Shinohara-Kanda A, et al. S-Mercuration of rat sorbitol dehydrogenase by methylmercury causes its aggregation and the release of the zinc ion from the active site[J]. Archives of toxicology, 2012, 86(11): 1693-1702. 22752181