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Curcumin is a non‐competitive and selective inhibitor of phosphorylase kinase
Author(s) -
Reddy Shrikanth,
Aggarwal Bharat B.
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)80232-7
Subject(s) - phosphorylase kinase , curcumin , autophosphorylation , kinase , chemistry , protein kinase inhibitor , biochemistry , protein kinase a , glycogen phosphorylase , cyclin dependent kinase 9 , protein kinase c , mitogen activated protein kinase kinase , enzyme , microbiology and biotechnology , biology
Recently, we reported that curcumin (diferuloylmethane) inhibits the growth of several different kinds of tumor cells. In order to investigate the mechanism of this inhibition, we examined the effects of curcumin on different protein kinases: highly purified protein kinase A (PkA), protein kinase C (PkC), protamine kinase (cPK), phosphorylase kinase (PhK), autophosphorylation‐activated protein kinase (AK) and pp60 c‐src tyrosine kinase. While all kinases tested were inhibited by curcumin, only PhK was completely inhibited at relatively lower concentrations. At around 0.1 mM curcumin, PhK, pp60 c‐src , PkC, PkA, AK, and cPK were inhibited by 98%, 40%, 15%, 10%, 1%, and 0.5%, respectively. Lineweaver‐Burk plot analysis indicated that curcumin is a non‐competitive inhibitor of PhK with a K i of 0.075 mM. Overall, our results indicate that curcumin is a potent and selective inhibitor of phosphorylase kinase, a key regulatory enzyme involved in the metabolism of glycogen. This has important implications for the anti‐proliferative effects of curcumin.