Allosteric regulation is an innate control in most metabolic and signalling cascades that enables living organisms to adapt to the changing environment by tuning the affinity and regulating the activity of target proteins. For a microscopic understanding of this process, a protein system has been designed in such a way that allosteric communication between the binding and allosteric site can be observed in both directions. To that end, an azobenzene-derived photoswitch has been linked to the α3-helix of the PDZ3 domain, arguably the smallest allosteric protein with a clearly identifiable binding and allosteric site. Photo-induced trans-to-cis isomerisation of the photoswitch increases the binding affinity of a small peptide ligand to the protein up to 120-fold, depending on temperature. At the same time, ligand binding speeds up the thermal cis-to-trans back-isomerisation rate of the photoswitch. Based on the energetics of the four states of the system (cis vs trans and ligand-bound vs free), the concept of an allosteric force is introduced, which can be used to drive chemical reactions.
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http://dx.doi.org/10.1038/s41467-020-19689-7 | DOI Listing |
Environ Int
January 2025
Fujian Provincial Key Laboratory of Transplant Biology, Fuzong Teaching Hospital (900th Hospital of Joint Logistic Support Force), Fujian University of Traditional Chinese Medicine, Fuzhou 350025, China; Laboratory of Basic Medicine, Fuzong Clinical Medical College of Fujian Medical University, Fuzhou 350025, China; Dongfang Hospital, Xiamen University, Fuzhou 350025, China; Organ Transplant Institute, 900th Hospital of Joint Logistic Support Force, Fuzhou 350025, China. Electronic address:
Heat waves are a significant environmental issue threatening global human health. Extreme temperatures can lead to various heat-related illnesses, with heatstroke being among the most severe. Currently, there are no effective treatments to mitigate the multi-organ damage caused by heatstroke.
View Article and Find Full Text PDFBiochemistry
January 2025
Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742, United States.
Protein Sci
January 2025
Division of Biophysics, Department of Physiology, Jichi Medical University, Shimotsuke, Tochigi, Japan.
Much is known about how allosteric effectors influence the equilibrium between the relaxed (R) and tense (T) states of hemoglobin (Hb), but little is known about how and to what extent the effectors lower the intrinsic O affinity of each allosteric state, especially the R-state. Here, we provide a thorough characterization of the O equilibria of effector-bound and unbound R-quaternary form crystals of horse Hb without a quaternary structural switching. In the absence of effectors, R crystals of horse Hb were shown to bind O noncooperatively with a very high affinity virtually identical to that of R crystals of human Hb.
View Article and Find Full Text PDFThe LOV2 domain is commonly harnessed as a source of light-based regulation in engineered optogenetic switches. In prior work, we used LOV2 to create a light-regulated Dihydrofolate Reductase (DHFR) enzyme and showed that structurally disperse mutations in DHFR were able to tune the allosteric response to light. However, it remained unclear how light allosterically activates DHFR, and how disperse mutations modulate the allosteric effect.
View Article and Find Full Text PDFChem Sci
December 2024
Department of Chemistry, Faculty of Technology, Tomas Bata University in Zlín Vavrečkova 5669 760 01 Zlín Czech Republic
Rotaxanes can be regarded as storage systems for their wheel components, which broadens their application potential as a complement to the supramolecular systems that retain a mechanically interlocked structure. However, utilising rotaxanes in this way requires a method to release the wheel while preserving the integrity of all molecular constituents. Herein, we present simple rotaxanes based on cucurbit[6]uril (CB6), with an axis equipped with an additional binding motif that enables the binding of another macrocycle, cucurbit[7]uril (CB7).
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