Angewandte Chemie International Edition 2021, 60 Comprehensive Analysis of Binding Sites in Tubulin. Tobias Mühlethaler, Dario Gioia, Andrea E.Review Marine Pharmacology in 2018: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis and Antiviral Activities Affecting the Immune and Nervous Systems, and other Miscellaneous Mechanisms of Action. Rodríguez, Orazio Taglialatela-Scafati, Fumiaki Nakamura, Nobuhiro Fusetani. This article is cited by 11 publications.

While these global effects do not change the binding affinity of 2-methoxy-5-(2,3,4-trimethoxyphenyl)-2,4,6-cycloheptatrien-1-one (MTC) (a reversible binder of the colchicine site), the binding affinity of a fluorescent analogue of GTP (Mant-GTP) at the nucleotide E-site is reduced from 12 ± 2 × 10 5 M –1 in the case of unmodified tubulin to 1.4 ± 0.3 × 10 5 M –1 in the case of the zampanolide tubulin adduct, indicating signal transmission between the taxane site and the colchicine and nucleotide sites of β-tubulin. The covalent binding of zampanolide to β-tubulin affects both the colchicine site, causing a change of the quantum yield of the bound ligand, and the exchangeable nucleotide binding site, reducing the affinity for the nucleotide. Tubulin activation by zampanolide does not affect its longitudinal oligomerization but does alter its lateral association properties.

In this study, we have characterized the biochemical properties of the covalently modified, activated tubulin dimer, and we have determined the effect of zampanolide on tubulin association and the binding of tubulin ligands at other binding sites. Zampanolide-ligated tubulin has the switch-activation loop (M-loop) in the assembly prone form and, thus, represents an assembly activated state of the protein. The marine natural product zampanolide and analogues thereof constitute a new chemotype of taxoid site microtubule-stabilizing agents with a covalent mechanism of action.

Prota Structure 2018 Activation