Site‐specific introduction of an electroactive label into a non‐electroactive enzyme (β‐lactamase I)

Abstract

A cysteine residue was introduced close to the active site of β‐lactamase I by site‐directed mutagenesis to replace tyrosine‐105 and was subsequently modified with an electroactive SH‐specific reagent, N ‐(2‐ferrocene‐ethyl)maleimide. The resulting modified enzyme became electroactive, showing good quasi‐reversible electrochemistry which was characteristic of the attached ferrocene moiety while retaining its specific enzymatic activity. In the presence of a suicide substrate, 6β‐iodopenicillanic acid, the redox potential shifted +20 mV suggesting that the label was sensitive to changes in the active site of the enzyme.

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Identifiers

DOI

10.1016/s0014-5793(96)01373-7

Journal

FEBS Letters

Year

1997