Premium
Acceleration of the Rate‐Limiting Step of Thioredoxin Folding by Replacement of its Conserved cis ‐Proline with (4 S )‐Fluoroproline
Author(s) -
Roderer Daniel,
Glockshuber Rudi,
Rubini Marina
Publication year - 2015
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.201500342
Subject(s) - isomerization , chemistry , protein folding , limiting , folding (dsp implementation) , context (archaeology) , phi value analysis , peptide , stereochemistry , thioredoxin , amino acid , kinetics , peptide bond , crystallography , biochemistry , enzyme , biology , catalysis , mechanical engineering , paleontology , physics , electrical engineering , quantum mechanics , engineering
The incorporation of the non‐natural amino acids (4 R )‐ and (4 S )‐fluoroproline (Flp) has been successfully used to improve protein stability, but little is known about their effect on protein folding kinetics. Here we analyzed the influence of (4 R )‐ and (4 S )‐Flp on the rate‐limiting trans ‐to‐ cis isomerization of the Ile75–Pro76 peptide bond in the folding of Escherichia coli thioredoxin (Trx). While (4 R )‐Flp at position 76 had essentially no effect on the isomerization rate in the context of the intact tertiary structure, (4 S )‐Flp accelerated the folding reaction ninefold. Similarly, tenfold faster trans ‐to‐ cis isomerization of Ile75–(4 S )‐Flp76 relative to Ile75–Pro76 was observed in the unfolded state of Trx. Our results show that the replacement of cis prolines by non‐natural proline analogues can be used for modulating the folding rates of proteins with cis prolyl‐peptide bonds in the native state.