N,N′-(1,4-Phenyl­ene)bis­(2-bromo-2-methyl­propanamide)

The mol­ecular structure of the title compound, C14H18Br2N2O2, has one half-mol­ecule in the asymmetric unit. The mol­ecule has a crystallographic inversion centre in the middle of the benzene ring. The C—C—N—C torsion angle between the benzene ring and the bromo­amide group is 149.2 (7)°. The crystal is stabilized by a strong inter­molecular N—H⋯O bond and weak C—H⋯O inter­actions. These contacts give rise to a three-dimensional network

Specific Recognition of Promoter G-Quadruplex DNAs by Small Molecule Ligands and Light-up Probes

G-Quadruplexes (G4s) are four-stranded nucleic acid structures whose underlying G-rich sequences are present across the chromosome and transcriptome. These highly structured elements are known to regulate many key biological functions such as replication, transcription, translation, and genomic stability, thereby providing an additional layer of gene regulation. G4s are structurally dynamic and diverse, and they can fold into numerous topologies. They are potential targets for small molecules, which can modulate their functions. To this end, myriad classes of small molecules have been developed and studied for their ability to bind and stabilize these unique structures. Though many of them can selectively target G4s over duplex DNA, only a few of them can distinguish one G4 topology from others. Design and development of G4-specific ligands are challenging owing to the subtle structural variations among G4 structures. However, screening assays and computational methods have identified a few classes of ligands that preferentially or specifically target the G4 topology of interest over others. This review focuses on the small molecules and fluorescent probes that specifically target human promoter G4s associated with oncogenes. Targeting promoter G4s could circumvent the issues such as undruggability and development of drug resistance associated with the protein targets. The ligands discussed here highlight that development of G4-specific ligands is an achievable goal in spite of the limited structural data available. The future goal is to pursue the development of G4-specific ligands endowed with drug-like properties for G4-based therapeutics and diagnostics

3-({[(1-Phenyl­eth­yl)sulfan­yl]methane­thio­yl}sulfan­yl)propanoic acid

In the title compound, C12H14O2S3, a chain transfer agent (CTA) used in polymerization, the dihedral angle between the aromatic ring and the CS3 grouping is 84.20 (10)°. In the crystal, carb­oxy­lic acid inversion dimers linked by pairs of O—H⋯O hydrogen bonds generate R 2 2(8) loops

2,4,6-Trimethyl-3,5-bis[(phenylcarbono­thioyl)sulfanylmethyl]benzyl benzenecarbodithioate

In the title compound C33H30S6, the three pendant methyl­ene benzodithio­ate groups lie to one side of the central benzene ring in a cis-cis-cis ‘tripod’ arrangement. The dihedral angles between the central benzene ring and the three pendant rings are 72.54 (4), 89.68 (4) and 86.74 (4)°. In the crystal structure, one of the benzene rings is disordered over two orientations in a 0.559 (13):0.441 (13) ratio

2-Oxo-4-trifluoro­meth­yl-2H-chromen-7-yl 2-bromo-2-methyl­propano­ate

In the title compound, C14H10BrF3O4, the coumarin ring system is almost plannar (r.m.s. deviation = 0.025 Å) and a short C—H⋯F contact occurs. The propano­ate fragment is orientated almost perpendicular to the ring [dihedral angle = 71.80 (12)°]. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, generating [100] chains

2-Bromo-2-methyl-N-(4-methyl-2-oxo-2H-chromen-7-yl)propanamide

In the title compound C14H14BrNO3, the coumarin ring system is almost planar (r.m.s. deviation = 0.008 Å) and an intra­molecular C—H⋯O inter­action generates an S(6) ring. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds, with the C=O unit of the coumarin ring system acting as the acceptor group, generating [010] C(8) chains. The chain connectivity is reinforced by two C—H⋯O inter­actions

Optochemical control of gene expression by photocaged guanine and riboswitches

Optical control of biomolecules via engineered proteins or photoactive small molecules has had a profound impact on biology. However, optochemical tools to control RNA functions in living cells are relatively limited. We synthesized a photoactivatable (photocaged) guanine to modulate gene expression under riboswitch control in both mammalian cells and Escherichia coli by light

Gas-Phase Synthesis for Label-Free Biosensors: Zinc-Oxide Nanowires Functionalized with Gold Nanoparticles

Metal oxide semiconductor nanowires have important applications in label-free biosensing due to their ease of fabrication and ultralow detection limits. Typically, chemical functionalization of the oxide surface is necessary for specific biological analyte detection. We instead demonstrate the use of gas-phase synthesis of gold nanoparticles (Au NPs) to decorate zinc oxide nanowire (ZnO NW) devices for biosensing applications. Uniform ZnO NW devices were fabricated using a vapor-solid-liquid method in a chemical vapor deposition (CVD) furnace. Magnetron-sputtering of a Au target combined with a quadrupole mass filter for cluster size selection was used to deposit Au NPs on the ZnO NWs. Without additional functionalization, we electrically detect DNA binding on the nanowire at sub-nanomolar concentrations and visualize individual DNA strands using atomic force microscopy (AFM). By attaching a DNA aptamer for streptavidin to the biosensor, we detect both streptavidin and the complementary DNA strand at sub-nanomolar concentrations. Au NP decoration also enables sub-nanomolar DNA detection in passivated ZnO NWs that are resilient to dissolution in aqueous solutions. This novel method of biosensor functionalization can be applied to many semiconductor materials for highly sensitive and label-free detection of a wide range of biomolecules

Progress and future challenges in gene vectors, gene therapy systems and gene expressions

Genetic engineering has made sizeable contributions to technical innovation, agriculture, and the development of pharmaceuticals. Various approaches were evolved to control the genetic cloth of cells using both viral and nonviral vector architectures. Gene therapy aims to reverse pathological traits with the aid of the use of viral and nonviral gene shipping mechanisms. Gene transfer motors have made massive strides in becoming more environmentally pleasant, much less risky, and nonimmunogenic, as well as making an allowance for lengthy-time period transgene expression. One of the most tough components of correctly enforcing gene healing treatments in the clinical putting is adjusting gene expression extremely tightly and constantly as and while it's required. This research work will cognizance on using viral vectors for gene concentrated on biological applications with various gene expressions. Due to improvements in viral vector engineering and superior gene regulatory systems to permit and adjust tightly therapeutic gene expression, the technology for using genes to offer a preferred treatment has confirmed to be an effective approac

Efficiency of Organelle Capture by Microtubules as a Function of Centrosome Nucleation Capacity: General Theory and the Special Case of Polyspermia

Transport of organelles along microtubules is essential for the cell metabolism and morphogenesis. The presented analysis derives the probability that an organelle of a given size comes in contact with the microtubule aster. The question is asked how this measure of functionality of the microtubule aster is controlled by the centrosome. A quantitative model is developed to address this question. It is shown that for the given set of cellular parameters, such as size and total tubulin content, a centrosome nucleation capacity exists that maximizes the probability of the organelle capture. The developed general model is then applied to the capture of the female pronucleus by microtubules assembled on the sperm centrosome, following physiologically polyspermic fertilization. This application highlights an unintuitive reflection of nonlinearity of the nucleated polymerization of the cellular pool of tubulin. The prediction that the sperm centrosome should lower its nucleation capacity in the face of the competition from the other sperm is a stark illustration of the new optimality principle. Overall, the model calls attention to the capabilities of the centrosomal pathway of regulation of the transport-related functionality of the microtubule cytoskeleton. It establishes a quantitative and conceptual framework that can guide experiment design and interpretation