title: Structural and Biochemical Characterization of the Interaction of Tubulin with Potent Natural Analogues of Podophyllotoxin.
abstract: Four natural analogues of podophyllotoxin obtained from the Mexican medicinal plant Bursera fagaroides, namely, acetyl podophyllotoxin (2), 5'-desmethoxy-β-peltatin A methyl ether (3), 7',8'-dehydro acetyl podophyllotoxin (4), and burseranin (5), have been characterized, and their interactions with tubulin have been investigated. Cytotoxic activity measurements, followed by immunofluorescence microscopy and flow cytometry studies, demonstrated that these compounds disrupt microtubule networks in cells and cause cell cycle arrest in the G2/M phase in the A549 cell line. A tubulin binding assay showed that compounds 1-4 were potent assembly inhibitors, displaying binding to the colchicine site with Kb values ranging from 11.75 to 185.0 × 10(5) M(-1). In contrast, burseranin (5) was not able to inhibit tubulin assembly. From the structural perspective, the ligand-binding epitopes of compounds 1-3 have been mapped using STD-NMR, showing that B and E rings are the major points for interaction with the protein. The obtained results indicate that the inhibition of tubulin assembly of this family of compounds is more effective when there are at least two methoxyl groups at the E ring, along with a trans configuration of the lactone ring in the aryltetralin lignan core.
authors: Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos , Cuernavaca, Morelos 62209, México.
authors: Mayra
authors: M
authors: Antúnez-Mojica
authors: Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas , Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors: Javier
authors: J
authors: Rodríguez-Salarichs
authors: Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas , Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors: Mariano
authors: M
authors: Redondo-Horcajo
authors: Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos , Cuernavaca, Morelos 62209, México.
authors: Alejandra
authors: A
authors: León
authors: Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas , Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors: Isabel
authors: I
authors: Barasoain
authors: Departamento de Química Orgánica I, Facultad Ciencias Químicas, Universidad Complutense de Madrid , Avenida Complutense s/n, 28040 Madrid, Spain.
authors: Ángeles
authors: Á
authors: Canales
authors: Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas , Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors: F J
authors: FJ
authors: Cañada
authors: CIC bioGUNE Parque Tecnológico de Bizkaia, Edif. 801A-1°, 48160 Derio-Bizkaia, Spain, and Ikerbasque, Basque Foundation for Science , Maria Diaz de Haro 3, 48009 Bilbao, Spain.
authors: Jesús
authors: J
authors: Jiménez-Barbero
authors: Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos , Cuernavaca, Morelos 62209, México.
authors: Laura
authors: L
authors: Alvarez
authors: Department of Chemical and Physical Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas , Ramiro de Maeztu 9, 28040 Madrid, Spain.
authors: J Fernando
authors: JF
authors: Díaz
mesh_terms: D031233:Bursera / Q000737:chemistry*; D002453:Cell Cycle / Q000187:drug effects; D003078:Colchicine / Q000494:pharmacology; D006801:Humans; D007783:Lactones / Q000737:chemistry / Q000494:pharmacology; D017705:Lignans / Q000494:pharmacology; D008870:Microtubules / Q000187:drug effects; D015394:Molecular Structure; D011034:Podophyllotoxin / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology*; D011485:Protein Binding; D014404:Tubulin / Q000378:metabolism*; D050257:Tubulin Modulators / Q000737:chemistry / Q000494:pharmacology
chemical_list: D007783:Lactones; D017705:Lignans; D014404:Tubulin; D050257:Tubulin Modulators; C010499:beta-peltatin A methyl ether; D011034:Podophyllotoxin; D003078:Colchicine