title: Inhibitory effects of Cefazolin and Cefodizime on the activity of mushroom tyrosinase.
abstract: Tyrosinase (EC 1.14.18.1) catalyzes both the hydroxylation of tyrosine into o-diphenols and the oxidation of o-diphenols into o-quinones that form brown or black pigments. In the present paper, the effects of Cefazolin and Cefodizime on the activity of mushroom tyrosniase have been studied. The results showed that the Cephalosporin antibacterial drugs (Cefazolin and Cefodizime) could inhibit both monophenolase activity and diphenolase activity of the enzyme. For the monophenolase activity, Both Cefazolin and Cefodizime could lengthen the lag time and decrease the steady-state activities, and the IC(50) values were estimated as 7.0 mM and 0.13 mM for monophenolase activity, respectively. For the diphenolase activity, the inhibitory capacity of Cefodizime was obviously stronger than that of Cefazolin, and the IC(50) values were estimated as 0.02 mM and 0.21 mM, respectively. Kinetic analyses showed that inhibition by both compounds was reversible and their mechanisms were competitive and mixed-type, respectively. Their inhibition constants were also determined and compared. The research may offer a lead for designing and synthesizing novel and effective tyrosinase inhibitors and also under the application field of Cephalosporins.
authors.affiliation: Key Laboratory for Chemical Biology of Fujian Province, School of Life Sciences, Xiamen University, Xiamen, China.
authors.forename: Jiang-Xing
authors.initials: JX
authors.lastname: Zhuang
authors.forename: Wen-Gang
authors.initials: WG
authors.lastname: Li
authors.forename: Ling
authors.initials: L
authors.lastname: Qiu
authors.forename: Xue
authors.initials: X
authors.lastname: Zhong
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Zhou
authors.forename: Qing-Xi
authors.initials: QX
authors.lastname: Chen
mesh_terms: D000363:Agaricales / Q000201:enzymology*; D002437:Cefazolin / Q000494:pharmacology*; D002439:Cefotaxime / Q000031:analogs & derivatives* / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D004791:Enzyme Inhibitors; D005656:Fungal Proteins / Q000037:antagonists & inhibitors; D020128:Inhibitory Concentration 50; D007700:Kinetics; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors*
chemical_list: D002511:Cephalosporins; D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D014442:Monophenol Monooxygenase; D002437:Cefazolin; D002439:Cefotaxime; C033356:cefodizime