Galactose 1-phosphate explained

D-Galactose-1-phosphate is an intermediate in the intraconversion of glucose and uridine diphosphate galactose.^[1] It is formed from galactose by galactokinase.The improper metabolism of galactose-1-phosphate is a characteristic of galactosemia.^[2] The Leloir pathway is responsible for such metabolism of galactose and its intermediate, galactose-1-phosphate. Deficiency of enzymes found in this pathway can result in galactosemia; therefore, diagnosis of this genetic disorder occasionally involves measuring the concentration of these enzymes.^[3] One of such enzymes is galactose-1-phosphate uridylyltransferase (GALT). The enzyme catalyzes the transfer of a UDP-activator group from UDP-glucose to galactose-1-phosphate. Although the cause of enzyme deficiency in the Leloir pathway is still disputed amongst researchers, some studies suggest that protein misfolding of GALT, which may lead to an unfavorable conformational change that impacts its thermal stability and substrate-binding affinity, may play a role in the deficiency of GALT in Type 1 galactosemia.^[4] Increase in galactitol concentration can be seen in patients with galactosemia; putting patients at higher risk for presenile cataract.^[5]

See also

• Galactose-1-phosphate uridylyltransferase

Notes and References

1. Book: https://www.ncbi.nlm.nih.gov/books/NBK441957/ . StatPearls. Galactose 1 Phosphate Uridyltransferase Deficiency (Galactosemia). StatPearls Publishing. 2018.
2. 10.1007/BF02143803. Galactose-1-phosphate in the pathophysiology of galactosemia. European Journal of Pediatrics. 154. S45–S49. 1995. Gitzelmann. R.. 7 Suppl 2. 7671964. 33277700.
3. McCorvie. Thomas J.. Gleason. Tyler J.. Fridovich-Keil. Judith L.. Timson. David J.. August 2013. Misfolding of galactose 1-phosphate uridylyltransferase can result in type I galactosemia. Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease. 1832. 8. 1279–1293. 10.1016/j.bbadis.2013.04.004. 23583749. 3679265. 0925-4439.
4. McCorvie. Thomas J.. Gleason. Tyler J.. Fridovich-Keil. Judith L.. Timson. David J.. August 2013. Misfolding of galactose 1-phosphate uridylyltransferase can result in type I galactosemia. Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease. 1832. 8. 1279–1293. 10.1016/j.bbadis.2013.04.004. 23583749. 3679265. 0925-4439.
5. Ficicioglu. Can. Hussa. Christie. Gallagher. Paul R. Thomas. Nina. Yager. Claire. 2010-07-01. Monitoring of Biochemical Status in Children with Duarte Galactosemia: Utility of Galactose, Galactitol, Galactonate, and Galactose 1-Phosphate. Clinical Chemistry. 56. 7. 1177–1182. 10.1373/clinchem.2010.144097. 20489133. 0009-9147. free.