Description_x000D_ General description_x000D_ Hexokinase (HK) from yeast is 486 amino acid containing enzyme with a α/β fold. It comprises a large and small domain separated by an active site cleft. Conserved glycine residues are essential for the ATP and glucose binding. The two isoforms are HKI and HKII encoded by HXK1 and HXK2 gene, respectively._x000D_ Application_x000D_ Hexokinase from Saccharomyces cerevisiae has been used:_x000D_ • to investigate its amyloid fibril forming tendency using biophysical methods_x000D_ • in tracking ATP depletion in peroxisomes and reticulocyte lysates in import assays_x000D_ • in the synthesis of Mg-ADP-actin from Mg-ATP actin monomers_x000D_ Packaging_x000D_ 1500 units in poly bottle_x000D_ Biochem/physiol Actions_x000D_ Catalyzes the phosphorylation of D-hexose sugars at the C6 position utilizing ATP as a phosphate source._x000D_ The rate of phosphorylation varies with different hexoses (pH 7.5, 30 °C)._x000D_ D-fructose KM: 0.33 mM_x000D_ D-glucose KM: 0.12 mM_x000D_ D-mannose KM: 0.05 mM_x000D_ Yeast hexokinase exists as two similar isoforms, PI and PII (A and B), with isoelectric points of 5.25 and 4, respectively._x000D_ Molecular Weight: ~ 54 kDa (monomer)_x000D_ ~110 kDa (dimer)_x000D_ Optimal pH: 7.5 to 9.0_x000D_ Extinction Coefficient: E1% = 8.85 (PI) and 9.47 (PII) at 280 nm_x000D_ Activators: Hexokinase requires Mg2+ ions (KM = 2.6 mM) for activity. Hexokinase is activated by catecholamines and related compounds._x000D_ Inhibitors: sorbose-1-phosphate, polyphosphates, 6-deoxy-6-fluoroglucose, 2-C-hydroxy-methylglucose, xylose, lyxose, and thiol reactive compounds (Hg2+ and 4-chloromercuribenzoate)_x000D_ Hexokinase II is a crucial enzyme in glucose metabolism. Deletion of gene in S. cerevisiae in the presence of high glucose displays oxidative growth and results in the production of high biomass as well as shortened diauxic shift. Hexokinase II is also involved in glucose repression._x000D_ Unit Definition_x000D_ One unit will phosphorylate 1.0 μmole of D-glucose per min at pH 7.6 at 25 °C, unless otherwise indicated below._x000D_ Physical form_x000D_ Lyophilized powder containing phosphate/citrate pH approx. 7.0_x000D_ Other Notes_x000D_ Predominantly the PII isoform, produced from an overexpressing yeast strain.