Josh Lawrence
@jmlawrence.bsky.social
Research Fellow at Trinity Hall and Chemistry Department of the University of Cambridge | he/him
Thanks to all the authors in Chris Howe's, @biophotoelectro.bsky.social and other labs who contributed over the years. Also to the fantastic (and super quick) editors and reviewers whose comments greatly improved the manuscript, as well as the BBSRC and others for funding. (10/10)
July 21, 2025 at 11:05 AM
Thanks to all the authors in Chris Howe's, @biophotoelectro.bsky.social and other labs who contributed over the years. Also to the fantastic (and super quick) editors and reviewers whose comments greatly improved the manuscript, as well as the BBSRC and others for funding. (10/10)
This technique (native membrane electrochemistry) combines the interpretability of protein electrochemistry with the complexity of microbial electrochemistry. We envision applications in investigating #bioenergetics, as well as #bioelectricity and #biocatalysis. (9/10)
July 21, 2025 at 11:05 AM
This technique (native membrane electrochemistry) combines the interpretability of protein electrochemistry with the complexity of microbial electrochemistry. We envision applications in investigating #bioenergetics, as well as #bioelectricity and #biocatalysis. (9/10)
We also identified how wiring membranes to electrodes has inherent advantages in #biohybrid devices for energy conversion. Here we obtain photocurrents at -600 mV vs SHE; ~1V more negative (much higher energy electrons) than is achievable with isolated proteins. (8/10)
July 21, 2025 at 11:05 AM
We also identified how wiring membranes to electrodes has inherent advantages in #biohybrid devices for energy conversion. Here we obtain photocurrents at -600 mV vs SHE; ~1V more negative (much higher energy electrons) than is achievable with isolated proteins. (8/10)
We also showed how these electrochemical measurements can be coupled to spectroscopy, with parameters from each showing agreement with one another. (7/10)
July 21, 2025 at 11:05 AM
We also showed how these electrochemical measurements can be coupled to spectroscopy, with parameters from each showing agreement with one another. (7/10)
This alone demonstrates that electrochemistry can interrogate complex biological systems, but what can we actually use it for? Here we use the Spike Charge to measure respiratory reduction and oxidation of the #quinone pool (↑Spike Charge = ↑quinone reduction). (6/10)
July 21, 2025 at 11:05 AM
This alone demonstrates that electrochemistry can interrogate complex biological systems, but what can we actually use it for? Here we use the Spike Charge to measure respiratory reduction and oxidation of the #quinone pool (↑Spike Charge = ↑quinone reduction). (6/10)
Through many experiments (different inhibitors, mutants, experimental conditions) we could disentangle the different electron transfer pathways within the membranes. This enabled us to create a detailed model of electron transfer between the membranes and the electrode. (5/10)
July 21, 2025 at 11:05 AM
Through many experiments (different inhibitors, mutants, experimental conditions) we could disentangle the different electron transfer pathways within the membranes. This enabled us to create a detailed model of electron transfer between the membranes and the electrode. (5/10)
These parameters were dependent on different interfacial electron transfer pathways, shown here by the different effects of photosynthetic inhibitors. This suggested analysis of photocurrents could provide information on different membrane electron transfer pathways! (4/10)
July 21, 2025 at 11:05 AM
These parameters were dependent on different interfacial electron transfer pathways, shown here by the different effects of photosynthetic inhibitors. This suggested analysis of photocurrents could provide information on different membrane electron transfer pathways! (4/10)
These specialised electrodes enabled sensitive measurements of photocurrents, revealing a distinct profile (not observed in previous studies) which was quantified as two parameters: the Spike Charge and the Steady State Photocurrent. (3/10)
July 21, 2025 at 11:05 AM
These specialised electrodes enabled sensitive measurements of photocurrents, revealing a distinct profile (not observed in previous studies) which was quantified as two parameters: the Spike Charge and the Steady State Photocurrent. (3/10)
To analyse bioelectrical pathways, we interfaced thylakoid membranes isolated from #cyanobacteria with structured #electrodes. These #membranes contain a highly complex network of electron transfer, including electron transport chains for #photosynthesis and #respiration. (2/10)
July 21, 2025 at 11:05 AM
To analyse bioelectrical pathways, we interfaced thylakoid membranes isolated from #cyanobacteria with structured #electrodes. These #membranes contain a highly complex network of electron transfer, including electron transport chains for #photosynthesis and #respiration. (2/10)
This work wouldn't have been possible without my fantastic colleagues in the Zhang lab (@biophotoelectro.bsky.social), Howe lab, and further afield. Also my funders @ukri.org, Leathersellers' foundation and Trinity Hall, who have supported this work which has bridged my PhD and fellowship. 15/15
March 19, 2025 at 4:41 PM
This work wouldn't have been possible without my fantastic colleagues in the Zhang lab (@biophotoelectro.bsky.social), Howe lab, and further afield. Also my funders @ukri.org, Leathersellers' foundation and Trinity Hall, who have supported this work which has bridged my PhD and fellowship. 15/15
Because cyanobacterial thylakoid membranes have some of the most complex electron transport pathways known to nature, the technique should be readily transferrable to any biological membrane. We foresee its use in characterising bioenergetic pathways and biohybrid systems. 14/15
March 19, 2025 at 4:41 PM
Because cyanobacterial thylakoid membranes have some of the most complex electron transport pathways known to nature, the technique should be readily transferrable to any biological membrane. We foresee its use in characterising bioenergetic pathways and biohybrid systems. 14/15
We think natural membrane electrochemistry sits nicely between protein electrochemistry and microbial electrochemistry in terms of data complexity and interpretibility, making it a perfect system for studying biological electron transport at a systems-level. 13/15
March 19, 2025 at 4:41 PM
We think natural membrane electrochemistry sits nicely between protein electrochemistry and microbial electrochemistry in terms of data complexity and interpretibility, making it a perfect system for studying biological electron transport at a systems-level. 13/15
This thread is a very high-level look at the manuscript which, like biolectrochemistry data, is very information-dense. All comments and questions are welcome! 12/15
March 19, 2025 at 4:41 PM
This thread is a very high-level look at the manuscript which, like biolectrochemistry data, is very information-dense. All comments and questions are welcome! 12/15
We also developed a spectroelectrochemistry set-up, which we used to prove that these changes in the Spike Charge matched biophysical measurements of plastoquinone pool reduction. 11/15
March 19, 2025 at 4:41 PM
We also developed a spectroelectrochemistry set-up, which we used to prove that these changes in the Spike Charge matched biophysical measurements of plastoquinone pool reduction. 11/15
In this graph we can see that the magnitude of the feature depends on the dark time (during which quinone reduction occurs), the addition of substrates for dehydrogenase enzymes which reduce the quinone pool, or the deletion of oxidase enzymes which oxidise the quinone pool. 10/15
March 19, 2025 at 4:41 PM
In this graph we can see that the magnitude of the feature depends on the dark time (during which quinone reduction occurs), the addition of substrates for dehydrogenase enzymes which reduce the quinone pool, or the deletion of oxidase enzymes which oxidise the quinone pool. 10/15
But how is this useful? To demonstrate the power of this technique, we used the Spike Charge feature to provide a direct electrochemical readout of plastoquinone pool reduction. 9/15
March 19, 2025 at 4:41 PM
But how is this useful? To demonstrate the power of this technique, we used the Spike Charge feature to provide a direct electrochemical readout of plastoquinone pool reduction. 9/15
To cut a (very long) story short, from these experiments we were able to build a model of the electron transfer processes happening within the isolated thylakoid membranes, and between them and the electrode. 8/15
March 19, 2025 at 4:41 PM
To cut a (very long) story short, from these experiments we were able to build a model of the electron transfer processes happening within the isolated thylakoid membranes, and between them and the electrode. 8/15
In addition to testing experimental conditions and mutants, the beauty of electrochemistry is that just by changing our electrode potential we could control which cofactors could transfer electrons to the electrode; as demonstrated in stepped chronoamperometry experiments like this one. 7/15
March 19, 2025 at 4:41 PM
In addition to testing experimental conditions and mutants, the beauty of electrochemistry is that just by changing our electrode potential we could control which cofactors could transfer electrons to the electrode; as demonstrated in stepped chronoamperometry experiments like this one. 7/15
We were were able to show how these two electrochemical parameters related to different thylakoid membrane electron transport pathways, including components of the photosynthetic and respiratory electron transport chains. Disentangling signals from these overlapping pathways is very difficult! 6/15
March 19, 2025 at 4:41 PM
We were were able to show how these two electrochemical parameters related to different thylakoid membrane electron transport pathways, including components of the photosynthetic and respiratory electron transport chains. Disentangling signals from these overlapping pathways is very difficult! 6/15
When recording photocurrents (change in current over a photoperiod) using these electrodes, we observed a unique profile which could be analysed using two electrochemical parameters: the Steady State Photocurrent and the Spike Charge. 5/15
March 19, 2025 at 4:41 PM
When recording photocurrents (change in current over a photoperiod) using these electrodes, we observed a unique profile which could be analysed using two electrochemical parameters: the Steady State Photocurrent and the Spike Charge. 5/15
Here, we use highly structured electrodes to perform sensitive electrochemical measurements of the thylakoid membranes of our favourite organisms, #cyanobacteria. These contain very complex electron transport pathways, with #photosynthesis and #respiration occuring in the same membranes. 4/15
March 19, 2025 at 4:41 PM
Here, we use highly structured electrodes to perform sensitive electrochemical measurements of the thylakoid membranes of our favourite organisms, #cyanobacteria. These contain very complex electron transport pathways, with #photosynthesis and #respiration occuring in the same membranes. 4/15
There has been some spectacular research in recent years on interfacing membranes and cell biofilms with electrodes (check the references for some of these). But the low sensitivity and high complexity of these analytes have hindered analysis of electron transport in these complex systems. 3/15
March 19, 2025 at 4:41 PM
There has been some spectacular research in recent years on interfacing membranes and cell biofilms with electrodes (check the references for some of these). But the low sensitivity and high complexity of these analytes have hindered analysis of electron transport in these complex systems. 3/15