Glycerokinase from Cellulomonas sp.

Research area: Cell Signaling

Glycerol kinase (GK) is part of the FGGY carbohydrate kinase family.

Isoelectric point : 4.2
Michaelis constants : 4.4 x 10^-5M (Glycerol), 4.3 x 10^-4M (ATP)
Inhibitors : p-Chloromercuribenzoate, heavy metal ions (Pb⁺⁺, Fe⁺⁺, Hg⁺⁺, Ag⁺)
Optimum pH : 9.8 (G-3-PDH system), 7.8 (G-3-P oxidase system) Optimum temperature : 500^C
pH Stability : pH 5.5 x 10.0 (25o^C, 20hr)
Thermal stability : below 40o^C (pH 7.5, 15min)
Substrate specificity : This enzyme catalyzes the stereospecific transfer of the terminal
phosphoryl moiety of ATP to one of the primary hydroxyl group of
glycerol, forming sn-glycerol-3-P. The enzyme has the highest
specificity for glycerol, and also phosphorylates dihydroxyacetone
and glyceraldehyde (Table 1,2). Mg+⁺ is essentially required for the
reaction.

Glycerokinase from Cellulomonas sp. has been used:

• for determining the kinetic characteristics of human and trypanosomatid phosphofructokinases using an enzyme-linked kinetic assay.
• to study the effect of sugar in fluorescence emission.
• in 2-Arachidonoylglycerol-based fluorescence assay for DH-463, a fluorescent activity-based probe for monoacylglycerol lipase.

Glycerol kinase catalyzes the MgATP-dependent phosphorylation of glycerol to produce sn-glycerol-3-phosphate and is the rate limiting enzyme in the utilization of glycerol. It is also subject to feedback regulation by fructose-1,6-bisphosphate.Mutations in this gene are associated with Glycerol Kinase Deficiency (GKD), a condition characterized primarily by hypertriglyceridemia and hypoglycemia. This enzyme is useful for enzymatic determination of glycerol and triglyceride when coupled with glycerol-3-phosphate dehydrogenase (=G-3-P DH, G3D-301), glycerol-3-phosphate oxidase (=G-3-P oxidase, G3O-301, G3O-311, G3O-321) or pyruvate kinase (PYK-301) and lactate dehydrogenase (LCD-209, LCD-211), lipoprotein lipase (LPL-311, LPL-314) in clinical analysis

Lyophilized powder containing phosphate buffer salts and sodium gluconate

One unit will convert 1.0 μmole of glycerol and ATP to L-α-glycerophosphate and ADP per min at pH 9.8 at 25 °C in a coupled system with PK/LDH.