Boldine-derived Alkaloids inhibit the activity of DNA topoisomerase I and growth of Mycobacterium tuberculosis

García, M.T. ; Carreño, D. ; Tirado-Vélez, J.M. ; Ferrándiz, M.J. ; Rodrigues, L. ; Gracia, B. (Universidad de Zaragoza) ; Amblar, M. ; Ainsa, J.A. (Universidad de Zaragoza) ; de la Campa, A.G.

Resumen: The spread of multidrug-resistant isolates of Mycobacterium tuberculosis requires the discovery of new drugs directed to new targets. In this study, we investigated the activity of two boldine-derived alkaloids, seconeolitsine (SCN) and N-methyl-seconeolitsine (N-SCN), against M. tuberculosis. These compounds have been shown to target DNA topoisomerase I enzyme and inhibit growth of Streptococcus pneumoniae. Both SCN and N-SCN inhibited M. tuberculosis growth at 1.95-15.6 µM, depending on the strain. In M. smegmatis this inhibitory effect correlated with the amount of topoisomerase I in the cell, hence demonstrating that this enzyme is the target for these alkaloids in mycobacteria. The gene coding for topoisomerase I of strain H37Rv (MtbTopoI) was cloned into pQE1 plasmid of Escherichia coli. MtbTopoI was overexpressed with an N-terminal 6-His-tag and purified by affinity chromatography. In vitro inhibition of MtbTopoI activity by SCN and N-SCN was tested using a plasmid relaxation assay. Both SCN and N-SCN inhibited 50% of the enzymatic activity at 5.6 and 8.4 µM, respectively. Cleavage of single-stranded DNA was also inhibited with SCN. The effects on DNA supercoiling were also evaluated in vivo in plasmid-containing cultures of M. tuberculosis. Plasmid supercoiling densities were -0.060 in cells untreated or treated with boldine, and -0.072 in 1 × MIC N-SCN treated cells, respectively, indicating that the plasmid became hypernegatively supercoiled in the presence of N-SCN. Altogether, these results demonstrate that the M. tuberculosis topoisomerase I enzyme is an attractive drug target, and that SCN and N-SCN are promising lead compounds for drug development.

Idioma: Inglés

DOI: 10.3389/fmicb.2018.01659

Año: 2018

Publicado en: Frontiers in Microbiology 9, JUL (2018), 1659 [9 pp]
ISSN: 1664-302X

Factor impacto JCR: 4.259 (2018)

Categ. JCR: MICROBIOLOGY rank: 32 / 133 = 0.241 (2018) - Q1 - T1

Factor impacto SCIMAGO: 1.633 - Microbiology (medical) (Q1) - Microbiology (Q1)

Financiación: info:eu-repo/grantAgreement/EC/FP7/260872/EU/More Medicines for Tuberculosis/MM4TB
Financiación: info:eu-repo/grantAgreement/ES/MINECO/BIO2009-09405
Financiación: info:eu-repo/grantAgreement/ES/MINECO/BIO2017-82951-R

Tipo y forma: Article (Published version)

Área (Departamento): Área Microbiología (Dpto. Microb.Med.Pr.,Sal.Públ.)
Área (Departamento): Proy. investigación HQA (Dpto. Microb.Med.Pr.,Sal.Públ.)