What does hexokinase II do?
Hexokinase II phosphorylates glucose to regulate glucose metabolism but also functions as a protective signaling molecule. Hexokinase II is the predominant isoform in insulin-sensitive tissues and upregulated in tumors. Hexokinase II expression is regulated by the Akt/mTOR pathway.
Where is hexokinase II found?
In particular, HK2 is ubiquitously expressed in tissues, though it is majorly found in muscle and adipose tissue. In cardiac and skeletal muscle, HK2 can be found bound to both the mitochondrial and sarcoplasmic membrane.
What type of biomolecule is hexokinase?
A hexokinase is an enzyme that phosphorylates hexoses (six-carbon sugars), forming hexose phosphate. In most organisms, glucose is the most important substrate for hexokinases, and glucose-6-phosphate is the most important product….
| Hexokinase | |
|---|---|
| EC no. | 2.7.1.1 |
| CAS no. | 9001-51-8 |
| Databases | |
| IntEnz | IntEnz view |
What causes hexokinase deficiency disease?
The cause of hexokinase deficiency is linked to mutations of the HK gene and the encoding of the HK enzyme. The result of the mutations lead to reduction in HK activity.
Why is hexokinase important?
Hexokinase activates glycoloysis by phosphorylating glucose. Since the phosphorylation of glucose to glucose-6-phosphate is the rate limiting step of glucose metabolism, hexokinase has a very important role in regulating healthy glucose levels in the human body [7].
What kind of enzyme is hexokinase?
Hexokinase is a protein which is classified under the main grouping of a transferase enzyme. Its structure was first determined from yeast by Tom Steitz at Yale University. Hexokinase is the first enzyme in the glycolytic pathway, and it converts glucose into glucose-6-phosphate.
What are the symptoms of hexokinase deficiency?
Signs and symptoms of hexokinase deficiency are very similar to those of pyruvate kinase deficiency but anemia is generally more severe. Some affected individuals reportedly have had various abnormalities in addition to NSHA including multiple malformations, panmyelopathy, and latent diabetes.
How would a hexokinase deficiency affect the oxygen affinity of hemoglobin?
The blood of a patient with a deficiency of hexokinase in the red cells and a decreased concentration of 2, 3-diphosphoglycerate in the red cells showed an increased affinity for oxygen, whereas a patient with a deficiency of pyruvate kinase and an elevated concentration of 2, 3-diphosphoglycerate in the red cells had …
Is hexokinase in the liver?
Hexokinase is a family of four enzymes including glucokinase, also called hexokinase IV in liver and pancreatic islet cells.
What is main function of hexokinase?
Hexokinase is the initial enzyme of glycolysis, catalyzing the phosphorylation of glucose by ATP to glucose-6-P. It is one of the rate-limiting enzymes of glycolysis. Its activity declines rapidly as normal red cells age.
What happens if hexokinase is inhibited?
Inhibition of HK will suppress glucose uptake because the intracellular glucose concentration will rise. In addition, because HK is inhibited allosterically by its product, G6P, a failure to dispose of G6P within the cell will cause HK inhibition.
What does high hexokinase mean?
In most cells a hexokinase with a high affinity for glucose—i.e., only small amounts of glucose are necessary for enzymatic activity—effects the reaction. In addition, the liver contains a glucokinase, which requires a much greater concentration of glucose before it reacts.