Intracellular vesicle fusion is catalyzed by soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs). Vesicle-anchored v-SNAREs pair with target membrane-associated t-SNAREs to form trans-SNARE complexes, releasing free energy to drive membrane fusion. However, trans-SNARE complexes are unable to assemble efficiently unless activated by Sec1/Munc18 (SM) proteins. Here, we demonstrate that SNAREs become fully active when the v-SNARE is split into two fragments, eliminating the requirement of SM protein activation. Mechanistically, v-SNARE splitting accelerates the zippering of trans-SNARE complexes, mimicking the stimulatory function of SM proteins. Thus, SNAREs possess the full potential to drive efficient membrane fusion but are suppressed by a conformational constraint. This constraint is removed by SM protein activation or v-SNARE splitting. We suggest that ancestral SNAREs originally evolved to be fully active in the absence of SM proteins. Later, a conformational constraint coevolved with SM proteins to achieve the vesicle fusion specificity demanded by complex endomembrane systems.
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http://dx.doi.org/10.1016/j.celrep.2020.108611 | DOI Listing |
Chem Sci
December 2024
ByteDance Research Bellevue Washington 98004 USA
A force field is a critical component in molecular dynamics simulations for computational drug discovery. It must achieve high accuracy within the constraints of molecular mechanics' (MM) limited functional forms, which offers high computational efficiency. With the rapid expansion of synthetically accessible chemical space, traditional look-up table approaches face significant challenges.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China. Electronic address:
Background: As global food production continues to surge, the widespread use of herbicides has also increased concurrently, posing challenges like health risks and environmental pollution. Traditional detection methods for pesticide residues, such as diquat (DQ), were hampered by limitations like high expenses, lengthy detection times and complex operations, restricting their practical application in rapid clinical diagnosis.
Results: In light of the pressing necessity for the identification of minute pesticide residues and the intrinsic constraints of small molecule analysis, a novel chromophotometric biosensor targeting small molecules was developed based on bi-epitopes on single antibody to immobilize two DQ-PAL, inhibiting the hybridization of DQ-PAL.
Anal Chim Acta
January 2025
School of Medical Devices, Shenyang Pharmaceutical University, No. 103, Wenhua Road, Shenyang, 110016, PR China. Electronic address:
Phenolic compounds are typical organic pollutants which cause severe human health problems due to their teratogenesis, carcinogenesis, neurotoxicity, immunotoxicity and endocrine disruption. Natural laccase is a multicopper oxidase existing in bacteria, plants, and insects, which can accelerate the transformation of phenolic compounds to their less hazardous oxidized products under mild conditions without harmful byproducts. Despite eco-environmentally friendly property of laccase, it still faces constraints of widespread application attribute to its high cost, complex preparation, and vulnerability.
View Article and Find Full Text PDFBiomolecules
November 2024
Department of Chemistry and Chemical Biology, Rutgers University, 123 Bevier Rd, Piscataway, NJ 08854, USA.
We demonstrate that a short oligonucleotide complementary to a G-quadruplex domain can invade this iconic, noncanonical DNA secondary structure in ways that profoundly influence the properties and differential occupancies of the resulting DNA polymorphic products. Our spectroscopic mapping of the conformational space of the associated reactants and products, both before and after strand invasion, yield unanticipated outcomes which reveal several overarching features. First, strand invasion induces the disruption of DNA secondary structural elements in both the invading strand (which can assume an iDNA tetrad structure) and the invaded species (a G-quadruplex).
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
State Key Laboratory of Elemento-organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
Pulsed dipolar electron paramagnetic resonance (PD-EPR) measurement is a powerful technique for characterizing the interactions and conformational changes of biomolecules. The extraction of these distance restraints from PD-EPR experiments relies on manipulation of spin-spin pairs. The orthogonal spin labeling approach offers unique advantages by providing multiple distances between different spin-spin pairs.
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