English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Inducible lysine decarboxylases (LDCs) are essential in various cellular processes of microorganisms and plants, especially under acid stress, which induces the expression of genes encoding LDCs. In this study, a novel Serratia marcesenes LDC (SmcadA) was successfully expressed in E. coli , purified and characterized. The protein had an optimal pH of 6 and a temperature of 40 °C and phylogenetic analysis to determine the evolution of SmcadA, which revealed a close relation to Enterobacteriaceae, Klebsiella sp., among others. The molecular weight of SmcadA was approximately 75 kDa after observation on SDS-PAGE and structural modeling showed the protein as a decamer, comprised of five interlinked dimers. The biocatalytic activity of the purified wild-type SmcadA (WT) was improved through site directed mutations and the results showed that the Arg595Lys mutant had the highest specific activity of 286.55 U/mg, while the Ser512Ala variant and wild-type SmcadA had 215.72 and 179.01 U/mg, respectively. Furthermore, molecular dynamics simulations revealed that interactions through hydrogen bonds between the protein residues and cofactor pyridoxal-5-phosphate (PLP) are vital for biocatalysis. Molecular Dynamics (MD) simulations also indicated that mutations conferred structural changes on protein residues and PLP hence altered the interacting residues with the cofactor, subsequently influencing substrate bioconversion. Moreover, the temperature also induced changes in orientation of cofactor PLP and amino acid residues. This work therefore demonstrates the successful expression and characterization of the purified novel lysine decarboxylase from Serratia marcesenes and provided insight into the mechanism of protein-cofactor interactions, highlighting the role of protein-ligand interactions in altering cofactor and binding site residue conformations, thus contributing to improved biocatalysis.

Biochemical Characterization and Structural Insight into Interaction and Conformation Mechanisms of Serratia marcescens Lysine Decarboxylase (SmcadA)