Having accumulated extensive experiences and experimental skills in the past years, Creative Enzymes has rapidly evolved to one of the most professional enzyme service companies. Relying on the in-depth expertise studies and the cutting-edge instruments, our scientist team has the capability to perform any enzyme testing. The phosphorylase kinase assays are based on the reliable spectrophotometric method.

Phosphorylase kinase (PHK) is the first protein kinase discovered. This enzyme specifically catalyzes the phosphorylation of a single serine residue, thereby converting inactive phosphorylase b (GPb) to active glycogen phosphorylase a (GPa). PHK requires Ca²⁺ and calmodulin for its activity.

Phosphorylase kinase (PHK) is a key enzyme involved in the control of glycogen degradation. The enzyme integrates extracellular signals. Combining signals arising from hormone receptor interactions or from neuronal impulses mediated through calcium, with those arising from intracellular events. By doing this, providing a tightly controlled kinase activity which regulates glycogen phosphorylase. The structure studies have shown that the enzyme is composed of four types of subunit, with stoichiometry (αβγδ)4. The α and β subunits are regulatory and are the targets for control by phosphorylation. The γ subunit is the catalytic subunit, and the δ subunit is essentially identical to calmodulin and confers calcium sensitivity. The deficiency of PHK has obvious clinical manifestations such as slow childhood body development and unusual enlargement of the liver. The disease can be defined by the abnormal reduce of catalytic activities. It can be seen that proper enzyme activity testing will contribute to the diagnose of disease. To facilitate such effort, Creative Enzymes offers targeted methods to meet different research needs.

Figure: The crystal structure of phosphorylase kinase from Oryctolagus cuniculus.
Reference: Skamnaki VT et al. Biochemistry. 1999 38(44): 14718-14730.

Creative Enzymes is one of the few companies which provides precise assays of phosphorylase kinase. The accurate testing method produces more reliable results than universal kinase activity kits. The capacity and flexibility of activity assays of Creative Enzymes impressed many customers. With the goal of ultimate performance on activity measurement, Creative Enzymes will never stop learning and progressing.