Exploring Intein Inhibition by Platinum Compounds as an Antimicrobial Strategy.
Inteins, self-splicing protein elements, interrupt genes and proteins in many microbes, including the human pathogen Mycobacterium tuberculosis Using conserved catalytic nucleophiles at their N- and C-terminal splice junctions, inteins are able to excise out of precursor polypeptides. The splicing of the intein in the mycobacterial recombinase RecA is specifically inhibited by the widely used cancer therapeutic cisplatin, cis-[Pt(NH3)2Cl2], and this compound inhibits mycobacterial growth. Mass spectrometric and crystallographic studies of Pt(II) binding to the RecA intein revealed a complex in which two platinum atoms bind at N- and C-terminal catalytic cysteine residues. Kinetic analyses of NMR spectroscopic data support a two-step binding mechanism in which a Pt(II) first rapidly interacts reversibly at the N terminus followed by a slower, first order irreversible binding event involving both the N and C termini. Notably, the ligands of Pt(II) compounds that are required for chemotherapeutic efficacy and toxicity are no longer bound to the metal atom in the intein adduct. The lack of ammine ligands and need for phosphine represent a springboard for future design of platinum-based compounds targeting inteins. Because the intein splicing mechanism is conserved across a range of pathogenic microbes, developing these drugs could lead to novel, broad range antimicrobial agents.
From the Department of Biological Sciences and RNA Institute and.|Howard P. Isermann Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180.
Hon
H
Chan
From the Department of Biological Sciences and RNA Institute and.|Howard P. Isermann Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180.
C Seth
CS
Pearson
From the Department of Biological Sciences and RNA Institute and.
Cathleen M
CM
Green
Laboratory of Computational and Structural Biology, Wadsworth Center, New York State Department of Health, Albany, New York 12208, and.
Zhong
Z
Li
Laboratory of Computational and Structural Biology, Wadsworth Center, New York State Department of Health, Albany, New York 12208, and.
Jing
J
Zhang
Howard P. Isermann Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180.
Georges
G
Belfort
Department of Chemistry, University at Albany, State University of New York, Albany, New York 12222.
Alex
A
Shekhtman
Laboratory of Computational and Structural Biology, Wadsworth Center, New York State Department of Health, Albany, New York 12208, and.|Department of Biomedical Sciences, University at Albany, State University of New York, Albany, New York 12201.
Hongmin
H
Li
From the Department of Biological Sciences and RNA Institute and mbelfort@albany.edu.
Marlene
M
Belfort
D000890:Anti-Infective Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002945:Cisplatin / Q000494:pharmacology*; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000378:metabolism*; D000072417:Protein Domains; D011938:Rec A Recombinases / Q000235:genetics / Q000378:metabolism*
D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D011938:Rec A Recombinases; D002945:Cisplatin
Mycobacterium tuberculosis; inhibition mechanism; intein; metal ion-protein interaction; protein drug interaction; protein splicing