A designed supramolecular protein assembly with in vivo enzymatic activity

作者：Song Woon Ju; Tezcan F Akif^*

来源：Science, 2014, 346(6216): 1525-1528.

DOI：10.1126/science.1259680

The generation of new enzymatic activities has mainly relied on repurposing the interiors of preexisting protein folds because of the challenge in designing functional, three-dimensional protein structures from first principles. Here we report an artificial metallo-beta-lactamase, constructed via the self-assembly of a structurally and functionally unrelated, monomeric redox protein into a tetrameric assembly that possesses catalytic zinc sites in its interfaces. The designed metallo-beta-lactamase is functional in the Escherichia coli periplasm and enables the bacteria to survive treatment with ampicillin. In vivo screening of libraries has yielded a variant that displays a catalytic proficiency [(k(cat)/K-m)/k(uncat)] for ampicillin hydrolysis of 2.3 x 10(6) and features the emergence of a highly mobile loop near the active site, a key component of natural beta-lactamases to enable substrate interactions.

• 出版日期2014-12-19