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The Scientific World Journal
Volume 2013, Article ID 678356, 7 pages
Research Article

An Inhibitive Enzyme Assay to Detect Mercury and Zinc Using Protease from Coriandrum sativum

1Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
2Biotechnology Research Centre, MARDI, P.O. Box 12301, 50774 Kuala Lumpur, Malaysia

Received 18 July 2013; Accepted 29 August 2013

Academic Editors: M. Y. Arica and B. C. Suedel

Copyright © 2013 Gunasekaran Baskaran et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Heavy metals pollution has become a great threat to the world. Since instrumental methods are expensive and need skilled technician, a simple and fast method is needed to determine the presence of heavy metals in the environment. In this study, an inhibitive enzyme assay for heavy metals has been developed using crude proteases from Coriandrum sativum. In this assay, casein was used as a substrate and Coomassie dye was used to denote the completion of casein hydrolysis. In the absence of inhibitors, casein was hydrolysed and the solution became brown, while in the presence of metal ions such as Hg2+ and Zn2+, the hydrolysis of casein was inhibited and the solution remained blue. Both Hg2+ and Zn2+ exhibited one-phase binding curve with IC50 values of 3.217 mg/L and 0.727 mg/L, respectively. The limits of detection (LOD) and limits of quantitation (LOQ) for Hg were 0.241 and 0.802 mg/L, respectively, while the LOD and LOQ for Zn were 0.228 and 0.761 mg/L, respectively. The enzyme exhibited broad pH ranges for activity. The crude proteases extracted from Coriandrum sativum showed good potential for the development of a rapid, sensitive, and economic inhibitive assay for the biomonitoring of Hg2+ and Zn2+ in the aquatic environments.