In Vitro Polymerization of Microtubules with a Fullerene Derivative

Fullerene derivative C60(OH)20 inhibited microtubule polymerization at low micromolar concentrations. The inhibition was mainly attributed to the formation of hydrogen bonding between the nanoparticle and the tubulin heterodimer, the building block of the microtubule, as evidenced by docking and mol...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:ACS nano 2011-08, Vol.5 (8), p.6306-6314
Hauptverfasser: Ratnikova, Tatsiana A, Nedumpully Govindan, Praveen, Salonen, Emppu, Ke, Pu Chun
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Fullerene derivative C60(OH)20 inhibited microtubule polymerization at low micromolar concentrations. The inhibition was mainly attributed to the formation of hydrogen bonding between the nanoparticle and the tubulin heterodimer, the building block of the microtubule, as evidenced by docking and molecular dynamics simulations. Our circular dichroism spectroscopy measurement indicated changes in the tubulin secondary structures, while our guanosine-5′-triphosphate hydrolysis assay showed hindered release of inorganic phosphate by the nanoparticle. Isothermal titration calorimetry revealed that C60(OH)20 binds to tubulin at a molar ratio of 9:1 and with a binding constant of 1.3 ± 0.16 × 106 M–1, which was substantiated by the binding site and binding energy analysis using docking and molecular dynamics simulations. Our simulations further suggested that occupancy by the nanoparticles at the longitudinal contacts between tubulin dimers within a protofilament or at the lateral contacts of the M-loop and H5 and H12 helices of neighboring tubulins could also influence the polymerization process. This study offered a new molecular-level insight on how nanoparticles may reshape the assembly of cytoskeletal proteins, a topic of essential importance for illuminating cell response to engineered nanoparticles and for the advancement of nanomedicine.
ISSN:1936-0851
1936-086X
DOI:10.1021/nn201331n