D-Galactose-1-phosphate is an intermediate in the intraconversion of

glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...

and uridine diphosphate galactose. It is formed from

galactose Galactose (, ''wikt:galacto-, galacto-'' + ''wikt:-ose#Suffix 2, -ose'', ), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweetness, sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epime ...

galactokinase Galactokinase is an enzyme (phosphotransferase) that facilitates the phosphorylation of galactose, α-D-galactose to galactose 1-phosphate at the expense of one molecule of adenosine triphosphate, ATP. Galactokinase catalyzes the second step of ...

.The improper metabolism of galactose-1-phosphate is a characteristic of

galactosemia Galactosemia (British galactosaemia, from Greek γαλακτόζη + αίμα, meaning galactose + blood, accumulation of galactose in blood) is a rare genetics, genetic Metabolism, metabolic Disease, disorder that affects an individual's ability t ...

. 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. One of such enzymes is

galactose-1-phosphate uridylyltransferase Galactose-1-phosphate uridyltransferase (or GALT, G1PUT) is an enzyme () responsible for converting ingested galactose to glucose. Galactose-1-phosphate uridyltransferase (GALT) catalyzes the second step of the Leloir pathway of galactose meta ...

(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. Increase in galactitol concentration can be seen in patients with galactosemia; putting patients at higher risk for presenile cataract.

References

{{Fructose and galactose metabolic intermediates Organophosphates Monosaccharide derivatives

See also

References