| 1. |
- Ashworth, Eleanor K., et al.
(författare)
-
Protomers of the green and cyan fluorescent protein chromophores investigated using action spectroscopy
- 2023
-
Ingår i: Physical Chemistry, Chemical Physics - PCCP. - 1463-9076 .- 1463-9084. ; 25:30, s. 20405-20413
-
Tidskriftsartikel (refereegranskat)abstract
- The photophysics of biochromophore ions often depends on the isomeric or protomeric distribution, yet this distribution, and the individual isomer contributions to an action spectrum, can be difficult to quantify. Here, we use two separate photodissociation action spectroscopy instruments to record electronic spectra for protonated forms of the green (pHBDI(+)) and cyan (Cyan(+)) fluorescent protein chromophores. One instrument allows for cryogenic (T = 40 & PLUSMN; 10 K) cooling of the ions, while the other offers the ability to perform protomer-selective photodissociation spectroscopy. We show that both chromophores are generated as two protomers when using electrospray ionisation, and that the protomers have partially overlapping absorption profiles associated with the S-1 & LARR; S-0 transition. The action spectra for both species span the 340-460 nm range, although the spectral onset for the pHBDI(+) protomer with the proton residing on the carbonyl oxygen is red-shifted by & AP;40 nm relative to the lower-energy imine protomer. Similarly, the imine and carbonyl protomers are the lowest energy forms of Cyan(+), with the main band for the carbonyl protomer red-shifted by & AP;60 nm relative to the lower-energy imine protomer. The present strategy for investigating protomers can be applied to a wide range of other biochromophore ions.
|
|
| 2. |
- Fry, Ellen L., et al.
(författare)
-
Vegetation type, not the legacy of warming, modifies the response of microbial functional genes and greenhouse gas fluxes to drought in Oro-Arctic and alpine regions
- 2023
-
Ingår i: FEMS microbiology ecology. - 1574-6941. ; 99:12
-
Tidskriftsartikel (refereegranskat)abstract
- Climate warming and summer droughts alter soil microbial activity, affecting greenhouse gas (GHG) emissions in Arctic and alpine regions. However, the long-term effects of warming, and implications for future microbial resilience, are poorly understood. Using one alpine and three Arctic soils subjected to in situ long-term experimental warming, we simulated drought in laboratory incubations to test how microbial functional-gene abundance affects fluxes in three GHGs: carbon dioxide, methane, and nitrous oxide. We found that responses of functional gene abundances to drought and warming are strongly associated with vegetation type and soil carbon. Our sites ranged from a wet, forb dominated, soil carbon-rich systems to a drier, soil carbon-poor alpine site. Resilience of functional gene abundances, and in turn methane and carbon dioxide fluxes, was lower in the wetter, carbon-rich systems. However, we did not detect an effect of drought or warming on nitrous oxide fluxes. All gene-GHG relationships were modified by vegetation type, with stronger effects being observed in wetter, forb-rich soils. These results suggest that impacts of warming and drought on GHG emissions are linked to a complex set of microbial gene abundances and may be habitat-specific.
|
|
| 3. |
- Mendonca, Tania, et al.
(författare)
-
OptoRheo : Simultaneous in situ micro-mechanical sensing and imaging of live 3D biological systems
- 2023
-
Ingår i: Communications Biology. - : Springer Nature. - 2399-3642. ; 6:1
-
Tidskriftsartikel (refereegranskat)abstract
- A new instrument named OptoRheo combines light sheet fluorescence microscopy and particle tracking microrheology for live imaging and micromechanical sensing of extracellular matrix-cell interactions. Biomechanical cues from the extracellular matrix (ECM) are essential for directing many cellular processes, from normal development and repair, to disease progression. To better understand cell-matrix interactions, we have developed a new instrument named 'OptoRheo' that combines light sheet fluorescence microscopy with particle tracking microrheology. OptoRheo lets us image cells in 3D as they proliferate over several days while simultaneously sensing the mechanical properties of the surrounding extracellular and pericellular matrix at a sub-cellular length scale. OptoRheo can be used in two operational modalities (with and without an optical trap) to extend the dynamic range of microrheology measurements. We corroborated this by characterising the ECM surrounding live breast cancer cells in two distinct culture systems, cell clusters in 3D hydrogels and spheroids in suspension culture. This cutting-edge instrument will transform the exploration of drug transport through complex cell culture matrices and optimise the design of the next-generation of disease models.
|
|
| 4. |
|
|
