Spectral Tuning of Azobenzene Photoswitches for Biological Applications

Sadovski, Oleg; Beharry, Andrew A.; Zhang, Fuzhong; Woolley, G. Andrew

doi:10.1002/anie.200805013

Cited by 223 publications

(127 citation statements)

References 22 publications

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“…However, high (e.g., pulsed) light intensities may be expected to populate the cis , cis -state and may permit pulsed-light-driven conformational changes. It is possible that further substitution, particularly in positions ortho to the azo units may slow down the thermal relaxation rates and make production of a large fraction of the cis , cis -species possible [28]. Alternatively, azobenzene-based switches with rapid thermal relaxation times are preferred in materials-based applications where they can lead to light-driven changes in polymer properties.…”

Section: Resultsmentioning

confidence: 99%

A bisazobenzene crosslinker that isomerizes with visible light

Samanta¹,

Qureshi²,

Woolley³

2012

Beilstein J. Org. Chem.

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Summary Background: Large conformational and functional changes of azobenzene-modified biomolecules require longer azobenzene derivatives that undergo large end-to-end distance changes upon photoisomerization. In addition, isomerization that occurs with visible rather than UV irradiation is preferred for biological applications. Results: We report the synthesis and characterization of a new crosslinker in which a central piperazine unit links two azobenzene chromophores. Molecular modeling indicates that this crosslinker can undergo a large change in end-to-end distance upon trans,trans to cis,cis isomerization. Photochemical characterization indicates that it does isomerize with visible light (violet to blue wavelengths). However, the thermal relaxation rate of this crosslinker is rather high (τ½ ~ 1 s in aqueous buffer at neutral pH) so that it is difficult to produce large fractions of the cis,cis-species without very bright light sources. Conclusion: While cis-lifetimes may be longer when the crosslinker is attached to a biomolecule, it appears the para-piperazine unit may be best suited for applications where rapid thermal relaxation is required.

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Section: Resultsmentioning

confidence: 99%

A bisazobenzene crosslinker that isomerizes with visible light

Samanta¹,

Qureshi²,

Woolley³

2012

Beilstein J. Org. Chem.

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“…This observation is as would be expected, because photoisomerization is dependent on the electronic transitions of the azobenzene group, which are affected by the electron-withdrawing/donating effects of substituents. [31,32] Photoswitching is influenced both by the overlap of the UV/Vis absorption bands with the UV/Vis filters used (selected on the basis of good wavelength overlap with the appropriate bands; data not shown) and by the relative stabilities of the E and Z isomers. Each of the compounds studied here contains an electron-withdrawing amide substituent on one aromatic ring and a variable substituent on the other (alkyne, amide, CH 2 -amide, or triazole).…”

Section: Resultsmentioning

confidence: 99%

Structural Optimization of Photoswitch Ligands for Surface Attachment of α‐Chymotrypsin and Regulation of Its Surface Binding

Pearson

Abell

2010

Chemistry A European J

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A modified gold surface that allows photoregulated binding of alpha-chymotrypsin has previously been reported. Here the development of this surface is reported, through the synthesis of a series of trifluoromethyl ketones and alpha-keto esters containing the azobenzene group and a surface attachment group as photoswitch inhibitors of alpha-chymotrypsin. All of the compounds are inhibitors of the enzyme, with activity that can be modulated by photoisomerization. The best photoswitch shows a reversible change in IC(50) inhibition constant of >5.3 times on photoisomerization. The trifluoromethyl ketone 1 exhibited excellent photoswitching and was attached to a gold surface in a two-step procedure involving an azide-alkyne cycloaddition. The resulting modified surface bound alpha-chymotrypsin to a degree that could be modulated by UV/Vis irradiation, showing "slow-tight" enzyme binding as observed for inhibitors in solution.

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“…Many of the phenyl ring substituents are known to alter the spectral characteristics of azobenzenes and this effect can be rationally utilized to design novel azobenzene derivatives (Rau, 1973; Beharry and Woolley, 2011). For example, electron donating groups at the ortho or para positions can red-shift the absorption spectrum of the trans isomer considerably (Chi et al, 2006; Sadovski et al, 2009; Beharry et al, 2011, 2008; Stawski et al, 2012). We have designed PCLs where the amide tail of AAQ was replaced by electron donating amine tails (see DENAQ and PhENAQ in Table 1).…”

Section: One-component Systems: Development and Tuning Of Photochromimentioning

confidence: 99%

Light at the end of the channel: optical manipulation of intrinsic neuronal excitability with chemical photoswitches

Mourot¹,

Tochitsky²,

Krämer³

2013

Front. Mol. Neurosci.

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Ion channels are transmembrane proteins that control the movement of ions across the cell membrane. They are the molecular machines that make neurons excitable by enabling the initiation and propagation of action potentials (APs). Rapid signaling within and between neurons requires complex molecular processes that couple the sensing of membrane voltage or neurotransmitter release to the fast opening and closing of the ion channel gate. Malfunction of an ion channel's sensing or gating module can have disastrous pathological consequences. However, linking molecular changes to the modulation of neural circuits and ultimately to a physiological or pathological state is not a straightforward task. It requires precise and sophisticated methods of controlling the function of ion channels in their native environment. To address this issue we have developed new photochemical tools that enable the remote control of neuronal ion channels with light. Due to its optical nature, our approach permits the manipulation of the nervous system with high spatial, temporal and molecular precision that will help us understand the link between ion channel function and physiology. In addition, this strategy may also be used in the clinic for the direct treatment of some neuronal disorders.

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Spectral Tuning of Azobenzene Photoswitches for Biological Applications

Cited by 223 publications

References 22 publications

A bisazobenzene crosslinker that isomerizes with visible light

A bisazobenzene crosslinker that isomerizes with visible light

Structural Optimization of Photoswitch Ligands for Surface Attachment of α‐Chymotrypsin and Regulation of Its Surface Binding

Light at the end of the channel: optical manipulation of intrinsic neuronal excitability with chemical photoswitches

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