Buffer-Dependent Photophysics of 2-Aminopurine: Insights into Fluorescence Quenching and Excited-State Interactions.

2-Aminopurine (2AP) is the most widely used fluorescent nucleobase analogue in DNA and RNA research. Its unique photophysical properties and sensitivity to environmental changes make it a useful tool for understanding nucleic acid dynamics and DNA-protein interactions. We studied the effect of ions present in commonly used buffer solutions on the excited-state photophysical properties of 2AP.

A new twist on PIFE: photoisomerisation-related fluorescence enhancement.

PIFE was first used as an acronym for protein-induced fluorescence enhancement, which refers to the increase in fluorescence observed upon the interaction of a fluorophore, such as a cyanine, with a protein. This fluorescence enhancement is due to changes in the rate of/photoisomerisation. It is clear now that this mechanism is generally applicable to interactions with any biomolecule.

A new twist on PIFE: photoisomerisation-related fluorescence enhancement.

PIFE was first used as an acronym for protein-induced fluorescence enhancement, which refers to the increase in fluorescence observed upon the interaction of a fluorophore, such as a cyanine, with a protein. This fluorescence enhancement is due to changes in the rate of cis/trans photoisomerisation. It is clear now that this mechanism is generally applicable to interactions with any biomolecule and, in this review, we propose that PIFE is thereby renamed according to its fundamental working principle as photoisomerisation-related fluorescence enhancement, keeping the PIFE acronym intact.

Evidence that the TRPV1 S1-S4 membrane domain contributes to thermosensing.

Sensing and responding to temperature is crucial in biology. The TRPV1 ion channel is a well-studied heat-sensing receptor that is also activated by vanilloid compounds, including capsaicin. Despite significant interest, the molecular underpinnings of thermosensing have remained elusive.

Crystallographic descriptions of regular 2-periodic weavings of threads, loops and nets.

Piecewise linear descriptions are presented of weavings of threads, loops and 2-periodic nets. Crystallographic data are provided for regular structures, defined as those with one kind (symmetry-related) of vertex (corner) and edge (stick). These include infinite families of biaxial thread weaves, interwoven square lattices (sql), honeycomb (hcb) nets, and tetragonal and hexagonal polycatenanes.

Implications of Human Transient Receptor Potential Melastatin 8 (TRPM8) Channel Gating from Menthol Binding Studies of the Sensing Domain.

The transient receptor potential melastatin 8 (TRPM8) ion channel is the primary cold sensor in humans. TRPM8 is gated by physiologically relevant cold temperatures and chemical ligands that induce cold sensations, such as the analgesic compound menthol. Characterization of TRPM8 ligand-gated channel activation will lead to a better understanding of the fundamental mechanisms that underlie TRPM8 function.