Glucose Transport and Glucose 6-Phosphate Hydrolysis in Intact Rat Liver Microsomes

The specificity of glucose 6-phosphatase of intact liver microsomes.

Permeability of rat liver microsomal membrane to glucose 6-phosphate.

Light-scattering measurements of osmotically induced changes in the size of rat liver microsomal vesicles pre-equilibrated in a low-osmolality buffer revealed the following. (1) The increase in extravesicular osmolality by addition of glucose 6-phosphate or mannose 6-phosphate (25 mM each) caused a rapid shrinking of microsomal vesicles. After shrinkage, a rapid swelling phase (t1/2 approx. 22 ...

Direct Evidence for the Involvement of Two Glucose 6-Phosphate-binding Sites in the Glucose-6-phosphatase Activity of Intact Liver Microsomes

S 5627 is a synthetic analogue of chlorogenic acid. S 5627 is a potent linear competitive inhibitor of glucose 6-phosphate (Glc-6-P) hydrolysis by intact microsomes (Ki 5 41 nM) but is without effect on the enzyme in detergentor NH4OH-disrupted microsomes. H-S 5627 was synthesized and used as a ligand in binding studies directed at characterizing T1, the Glc-6-P transporter. Binding was evaluat...

Glucose 6-phosphate transport in fibroblast microsomes from glycogen storage disease type 1b patients: evidence for multiple glucose 6-phosphate transport systems.

In liver endoplasmic reticulum the intralumenal glucose-6-phosphatase activity requires the operation of a glucose 6-phosphate transporter (G6PT1). Mutations in the gene encoding G6PT1 cause glycogen storage disease type 1b, which is characterized by a loss of glucose-6-phosphatase activity and impaired glucose homoeostasis. We describe a novel glucose 6-phosphate (G6P) transport activity in mi...

Glucose-6-Phosphate Dehydrogenase Deficiency and Neonatal Hyperbilirubinemia

Background: Jaundice is affecting over 60-80 percent of neonates in the first week of life. Glucose-6-phosphate dehydrogenase (G6PD) deficiency, which is an important cause of pathologic hyperbilirubinemia, can lead to hemolytic anemia, jaundice and kernicterus. The present study was performed to determine the prevalence of G6PD deficiency among icteric neonates in Shirvan, Iran. Methods: This...