Hyerin Kim1, Young Joo Yeon2, Yoo Rae Choi1, Wooho Song1, Seung Pil Pack3, Yoo Seong Choi4. 1. Department of Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon, 305-764, Korea. 2. School of Chemical and Biological Engineering, Seoul National University, Seoul, 151-742, Korea. 3. Department of Biotechnology and Bioinformatics, Korea University, Sejong, 339-700, Korea. spack@korea.ac.kr. 4. Department of Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon, 305-764, Korea. biochoi@cnu.ac.kr.
Abstract
OBJECTIVES: To obtain an acidic and cold-active tyrosinase, which potentially minimizes unwanted self-oxidation of tyrosinase-catalyzed catechols, including 3,4-dihydroxyphenylalanine at elevated pH and high temperature. RESULTS: A putative psychrophilic tyrosinase (named as tyrosinase-CNK) was identified from the genome information of the marine archaeon Candidatus Nitrosopumilus koreensis. This protein contains key tyrosinase domains, such as copper-binding domains and an O2-binding motif, and phylogenetic analysis revealed that it was distinct from other known bacterial tyrosinases. Functional tyrosinase-CNK was produced by applying a co-expression strategy together with chaperone proteins in Escherichia coli with a yield of approx. 30 mg l(-1) and a purity >95 %. The purified enzyme showed optimal activity at pH 6 and 20 °C and still had 50 % activity at 0 °C. Surprisingly, the enzyme exhibited an abnormally high monophenolase/diphenolase activity ratio. CONCLUSIONS: The acidic and cold-adapted tyrosinase-CNK, as a new type of tyrosinase, could expand potential applications of tyrosinases including the production of catechols through minimizing unwanted self-oxidation and the modification of existing materials at low temperature.
OBJECTIVES: To obtain an acidic and cold-active tyrosinase, which potentially minimizes unwanted self-oxidation of tyrosinase-catalyzed catechols, including 3,4-dihydroxyphenylalanine at elevated pH and high temperature. RESULTS: A putative psychrophilic tyrosinase (named as tyrosinase-CNK) was identified from the genome information of the marine archaeon Candidatus Nitrosopumilus koreensis. This protein contains key tyrosinase domains, such as copper-binding domains and an O2-binding motif, and phylogenetic analysis revealed that it was distinct from other known bacterial tyrosinases. Functional tyrosinase-CNK was produced by applying a co-expression strategy together with chaperone proteins in Escherichia coli with a yield of approx. 30 mg l(-1) and a purity >95 %. The purified enzyme showed optimal activity at pH 6 and 20 °C and still had 50 % activity at 0 °C. Surprisingly, the enzyme exhibited an abnormally high monophenolase/diphenolase activity ratio. CONCLUSIONS: The acidic and cold-adapted tyrosinase-CNK, as a new type of tyrosinase, could expand potential applications of tyrosinases including the production of catechols through minimizing unwanted self-oxidation and the modification of existing materials at low temperature.
Authors: Casey S Mogilevsky; Marco J Lobba; Daniel D Brauer; Alan M Marmelstein; Johnathan C Maza; Jamie M Gleason; Jennifer A Doudna; Matthew B Francis Journal: J Am Chem Soc Date: 2021-08-12 Impact factor: 16.383