A cold-adapted tyrosinase with an abnormally high monophenolase/diphenolase activity ratio originating from the marine archaeon Candidatus Nitrosopumilus koreensis

作者：Kim Hyerin; Yeon Young Joo; Choi Yoo Rae; Song Wooho; Pack Seung Pil^*; Choi Yoo Seong^*

来源：Biotechnology Letters, 2016, 38(9): 1535-1542.

DOI：10.1007/s10529-016-2125-0

• Acidic cold-active tyrosinase
• Co-expression
• Cold-active tyrosinase
• 3,4-Dihydroxyphenylalanine (DOPA)
• Marine archaea
• Psychrophilic enzyme
• Tyrosinase

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.
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 O-2-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 A degrees C and still had 50 % activity at 0 A degrees C. Surprisingly, the enzyme exhibited an abnormally high monophenolase/diphenolase activity ratio.
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.

• 出版日期2016-9