Highly active extracellular α-class carbonic anhydrase of Cyanothece sp. ATCC 51142.

Highly active extracellular α-class carbonic anhydrase of Cyanothece sp. ATCC 51142. Biochimie. 2019 Mar 18;: Authors: Kupriyanova EV, Sinetova MA, Mironov KS, Novikova GV, Dykman LA, Rodionova MV, Gabrielyan DA, Los DA Abstract Here, for the first time, we report the presence of highly active extracellular carbonic anhydrase (CA) of α-class in cyanobacterial cells. The enzyme activity was confirmed both in vivo in intact cells and in vitro, using the recombinant protein. CA activity in intact cells of Cyanothece sp. ATCC 51142 reached ∼ 0.6 Wilbur-Anderson units (WAU) per 1 mg of total cell protein, and it was inhibited by a specific CAs inhibitor, ethoxyzolamide. The genes cce_4328 (ecaA) and cce_0871 (ecaB), encoding two potential extracellular CAs of Cyanothece have been cloned, and the corresponding proteins EcaA and EcaB, representing CAs of α- and β-class, respectively, have been heterologously expressed in Escherichia coli. High specific activity (∼1.1×104 WAU per 1 mg of target protein) was detected for the recombinant EcaA only. The presence of EcaA in the outer cellular layers of Cyanothece was confirmed by immunological analysis with antibodies raised against the recombinant protein. The absence of redox regulation of EcaA activity indicates that this protein does not possess a disulfide bond essential for some α-class CAs. The content and activity of EcaA in a fraction of periplasmic proteins was higher in Cyan...
Source: Biochimie - Category: Biochemistry Authors: Tags: Biochimie Source Type: research