Construction of a novel redox protein by rational design: conversion of a disulfide bridge into a mononuclear iron-sulfur center.

Published

Journal Article

A mononuclear iron-sulfur center, capable of reversible electron transfer, has been introduced into thioredoxin, a protein devoid of such sites, using an automated, structure-based design algorithm. One of the sites predicted by the Dezymer computer program to introduce a tetrahedral tetrathiolate iron center included the intrinsic Cys32-Cys35 disulfide of wild-type thioredoxin and two additional mutants, Trp28Cys and Ile75Cys, thereby converting a disulfide into a metal-based redox center. This designed protein forms a 1:1 monomeric complex with FeIII, whose electronic absorption and EPR spectra closely resemble those of the rubredoxins, as intended. CoII spectra provided further confirmation of tetrahedral tetrathiolate metal coordination. The designed protein is capable of undergoing successive cycles of oxidation and reduction. The computer-generated design only took into account the geometry of the primary coordination shell around the metal. We have therefore demonstrated that simple geometrical considerations can be sufficient to reproduce the dominant electronic structure and reactivity of a simple metal-based redox center.

Full Text

Duke Authors

Cited Authors

  • Benson, DE; Wisz, MS; Liu, W; Hellinga, HW

Published Date

  • May 19, 1998

Published In

Volume / Issue

  • 37 / 20

Start / End Page

  • 7070 - 7076

PubMed ID

  • 9585516

Pubmed Central ID

  • 9585516

International Standard Serial Number (ISSN)

  • 0006-2960

Digital Object Identifier (DOI)

  • 10.1021/bi980583d

Language

  • eng

Conference Location

  • United States