Conformational changes in tubulin upon binding cryptophycin-52 reveal its mechanism of action
Autor: | Paul T. Wingfield, Norman R. Watts, Dan L. Sackett, Elif Eren |
---|---|
Rok vydání: | 2021 |
Předmět: |
Conformational change
Lactams cryptophycin-1 cyclodepsipeptide macromolecular substances Biochemistry Cryptophycin 52 Microtubule polymerization Cp-1 cryptophycin-1 Lactones conformational change Protein Domains Microtubule PDB Protein Data Bank Depsipeptides medicine maytansine site Structure–activity relationship Humans anticancer drug Binding site Molecular Biology biology Chemistry Cryoelectron Microscopy Cell Biology cryptophycin-52 Cp cryptophycin MD molecular dynamics MICEF Multi-Institute Cryo-EM Facility Cp-52 cryptophycin-52 Tubulin Mechanism of action tubulin Biophysics biology.protein cryo-EM medicine.symptom LY355703 HeLa Cells Research Article microtubule |
Zdroj: | The Journal of Biological Chemistry |
ISSN: | 1083-351X |
Popis: | Cryptophycin-52 (Cp-52) is potentially the most potent anticancer drug known, with IC50 values in the low picomolar range, but its binding site on tubulin and mechanism of action are unknown. Here, we have determined the binding site of Cp-52, and its parent compound, cryptophycin-1, on HeLa tubulin, to a resolution of 3.3 A and 3.4 A, respectively, by cryo-EM and characterized this binding further by molecular dynamics simulations. The binding site was determined to be located at the tubulin interdimer interface and partially overlap that of maytansine, another cytotoxic tubulin inhibitor. Binding induces curvature both within and between tubulin dimers that is incompatible with the microtubule lattice. Conformational changes occur in both α-tubulin and β-tubulin, particularly in helices H8 and H10, with distinct differences between α and β monomers and between Cp-52-bound and cryptophycin-1-bound tubulin. From these results, we have determined: (i) the mechanism of action of inhibition of both microtubule polymerization and depolymerization, (ii) how the affinity of Cp-52 for tubulin may be enhanced, and (iii) where linkers for targeted delivery can be optimally attached to this molecule. |
Databáze: | OpenAIRE |
Externí odkaz: |