An NIR-emitting probe (λem~700 nm) with a large Stokes shift (Δλ≈234 nm) is synthesized by using excited-state intramolecular proton transfer (ESIPT). The phenolic proton, which controls ESIPT, acts as a switch to give strong fluorescence at pH≈5. The probe can selectively show lysosome organelles, therefore leading to a lysosome probe without exhibiting “an alkalinizing effect”.
Programmed cell death (PCD) is a critical biological process involved in many important processes, and defects in PCD have been linked with numerous human diseases. In recent years, the protein architecture in different PCD subroutines has been explored, but our understanding of the global network organization of the noncoding RNA (ncRNA)-mediated cell death system is limited and ambiguous. Hence, we developed the comprehensive bioinformatics resource (ncRDeathDB, www.rna-society.org/ncrdeathdb ) to archive ncRNA-associated cell death interactions. The current version of ncRDeathDB documents a total of more than 4600 ncRNA-mediated PCD entries in 12 species. ncRDeathDB provides a user-friendly interface to query, browse and manipulate these ncRNA-associated cell death interactions. Furthermore, this resource will help to visualize and navigate current knowledge of the noncoding RNA component of cell death and autophagy, to uncover the generic organizing principles of ncRNA-associated cell death systems, and to generate valuable biological hypotheses.
Flavonoids have emerged to be an important molecular frame for chemical sensors, due to their capability to give dual emission and their compatibility to biological cells. Two flavonoid compounds with MeN- and EtN-substituents were examined by acquiring their fluorescence at different temperatures, in order to evaluate the impact of intramolecular charge transfer (ICT) on ESIPT. By freezing the sample solution in liquid N, the study detected the "locally excited" state at λ ≈ 460 nm, in which both ICT and ESIPT processes were not present. As temperature was warmed up (to about -90 °C), ICT process became gradually allowed and emission was shifted to λ ≈ 510 nm, which was attributed to the normal form N* of flavonoid. Emission from tautomeric form T* (λ ≈ 575 nm) could only be observed at a higher temperature, when ESIPT became allowed. With the aid of a model compound (without RN-substituent) and computational study, the study led to improved understanding on the photophysical properties of flavonoid materials in general.
Increasing evidence reveals that diverse non-coding RNAs (ncRNAs) play critically important roles in viral infection. Viruses can use diverse ncRNAs to manipulate both cellular and viral gene expression to establish a host environment conducive to the completion of the viral life cycle. Many host cellular ncRNAs can also directly or indirectly influence viral replication and even target virus genomes. ViRBase (http://www.rna-society.org/virbase) aims to provide the scientific community with a resource for efficient browsing and visualization of virus-host ncRNA-associated interactions and interaction networks in viral infection. The current version of ViRBase documents more than 12 000 viral and cellular ncRNA-associated virus–virus, virus–host, host–virus and host–host interactions involving more than 460 non-redundant ncRNAs and 4400 protein-coding genes from between more than 60 viruses and 20 hosts. Users can query, browse and manipulate these virus–host ncRNA-associated interactions. ViRBase will be of help in uncovering the generic organizing principles of cellular virus–host ncRNA-associated interaction networks in viral infection.
Two-photon
excitable (850 nm) NIR fluorescent turn-on (702 nm)
probe TP-NIR was synthesized for selective detection of cysteine (Cys).
The probe itself shows is turned on by reaction with Cys in aqueous
buffer. In addition, the probe displays greater selectivity for Cys
over other thiols, including glutathione (GSH) and homocysteine (Hcy).
Moreover, the large Stokes shift, NIR excitation, and NIR emission
make this probe suitable for biological imaging.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.