9F8G image
Deposition Date 2024-05-06
Release Date 2024-09-04
Last Version Date 2024-09-04
Entry Detail
PDB ID:
9F8G
Keywords:
Title:
Photostatin (photoswitchable azo-combretastatin) Z-PST27 bound to tubulin-DARPin D1 complex
Biological Source:
Source Organism:
Bos taurus (Taxon ID: 9913)
synthetic construct (Taxon ID: 32630)
Host Organism:
Method Details:
Experimental Method:
Resolution:
2.20 Å
R-Value Free:
0.22
R-Value Work:
0.18
R-Value Observed:
0.18
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Tubulin alpha-1B chain
Chain IDs:A
Chain Length:451
Number of Molecules:1
Biological Source:Bos taurus
Polymer Type:polypeptide(L)
Molecule:Tubulin beta-2B chain
Gene (Uniprot):TUBB2B
Chain IDs:B
Chain Length:445
Number of Molecules:1
Biological Source:Bos taurus
Polymer Type:polypeptide(L)
Molecule:Designed Ankyrin Repeat Protein (DARPIN) D1
Chain IDs:C (auth: F)
Chain Length:169
Number of Molecules:1
Biological Source:synthetic construct
Primary Citation
A photo-SAR study of photoswitchable azobenzene tubulin-inhibiting antimitotics identifying a general method for near-quantitative photocontrol.
Chem Sci 15 12301 12309 (2024)
PMID: 39118608 DOI: 10.1039/d4sc03072a

Abstact

Azobenzene analogues of the tubulin polymerisation inhibitor combretastatin A4 (PSTs) were previously developed to optically control microtubule dynamics in living systems, with subsecond response time and single-cell spatial precision, by reversible in situ photoswitching of their bioactivity with near-UV/visible light. First-generation PSTs were sufficiently potent and photoswitchable for use in live cells and embryos. However, the link between their seconds-scale and hours-scale bioactivity remained untested. Furthermore, the scope for modifications to tune their photo-structure-activity-relationship or expand their function was unknown. Here, we used large-field-of-view, long-term tandem photoswitching/microscopy to reveal the temporal onset of cytostatic effects. We then synthesised a panel of novel PSTs exploring structural variations that tune photoresponse wavelengths and lipophilicity, identifying promising blue-shifted analogues that are better-compatible with GFP/YFP imaging. Taken together, these results can guide new design and applications for photoswitchable microtubule inhibitors. We also identified tolerated sites for linkers to attach functional cargos; and we tested fluorophores, aiming at RET isomerisation or reporter probes. Instead we found that these antennas greatly enhance long-wavelength single-photon photoisomerisation, by an as-yet un-explored mechanism, that can now drive general progress towards near-quantitative long-wavelength photoswitching of photopharmaceuticals in living systems, with minimal molecular redesign and broad scope.

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