Open AccessInsight into the dimer dissociation process of the Chromobacterium violaceum (S)-selective amine transaminase
Author(s) -
Federica Ruggieri,
Jonatan C. Campillo-Brocal,
Shan Chen,
Maria Svedendahl Humble,
Björn Walse,
Derek Logan,
Per Berglund
Publication year - 2019
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/s41598-019-53177-3
Subject(s) - chromobacterium violaceum , transaminase , lysine , chemistry , dimer , protein engineering , enzyme , biochemistry , stereochemistry , amino acid , organic chemistry , quorum sensing , virulence , gene
One of the main factors hampering the implementation in industry of transaminase-based processes for the synthesis of enantiopure amines is their often low storage and operational stability. Our still limited understanding of the inactivation processes undermining the stability of wild-type transaminases represents an obstacle to improving their stability through enzyme engineering. In this paper we present a model describing the inactivation process of the well-characterized ( S )-selective amine transaminase from Chromobacterium violaceum . The cornerstone of the model, supported by structural, computational, mutagenesis and biophysical data, is the central role of the catalytic lysine as a conformational switch. Upon breakage of the lysine-PLP Schiff base, the strain associated with the catalytically active lysine conformation is dissipated in a slow relaxation process capable of triggering the known structural rearrangements occurring in the holo-to-apo transition and ultimately promoting dimer dissociation. Due to the occurrence in the literature of similar PLP-dependent inactivation models valid for other non-transaminase enzymes belonging to the same fold-class, the role of the catalytic lysine as conformational switch might extend beyond the transaminase enzyme group and offer new insight to drive future non-trivial engineering strategies.