Concurrent binding and delivery of proteins and lipophilic small molecules using polymeric nanogels

Supramolecular nanoassemblies, which are capable of binding and delivering either lipophilic small molecules or hydrophilic molecules, are of great interest. Concurrently binding and delivering this combination of molecules is cumbersome, because of the opposing supramolecular host requirements. We describe the development of a versatile nanoassembly system that is capable of binding and delivering both, a protein and a lipophilic small molecule, simultaneously inside the cells.     

Probing structural effects on replication efficiency through comparative analyses of families of potential self-replicators

A formidable synthetic apparatus for the creation of nanoscale molecular structures and supramolecular assemblies through molecular structures can potentially be created from systems that are capable of parallel automultiplication (self-replication). In order to achieve this goal, a detailed understanding of the relationship between molecular structure and replication efficiency is necessary. Diastereoisomeric templates that are capable of specific and simultaneous autocatalysis have been synthesised. A systematic experimental and theoretical evaluation of their behaviour and that of structurally-related systems reveals the key determinants that dictate the emergence of self-replicative function and defines the structural space within which this behaviour is observed.     

Evaluation of α-pyrones and pyrimidones as photoaffinity probes for affinity-based protein profiling

α-Pyrones and pyrimidones are common structural motifs in natural products and bioactive compounds. They also display photochemistry that generates high-energy intermediates that may be capable of protein reactivity. A library of pyrones and pyrimidones was synthesized, and their potential to act as photoaffinity probes for nondirected affinity-based protein profiling in several crude cell lysates was evaluated. Further "proof-of-principle" experiments demonstrate that a pyrimidone tag on an appropriate scaffold is equally capable of proteome labeling as a benzophenone.     

A FACTOR FROM GRANULOSA CELLS CAN STIMULATE OOCYTE TISSUE PLASMINOGEN ACTIVATOR ACTIVITY

Several studies indicate that substances synthesized by granulosa cells are capableof regulating oocyte activity. We have studied the effect of factors synthesized by gran-ulosa cells on tPA activity of denuded oocytes using a co- culture system. The resultsshow that an FSH- dependent factor(s) synthesized by granulosa cells (but not by theca-interstitial cells) is capable of stimulating tPA activity of denuded oocytes. This findingis important for understanding hormonal regulation of oocyte tPA activity by mediatorssynthesized in granulosa cells.     

A factor from granulosa cells can stimulate oocyte tissue plasminogen activator activity

Several studies indicate that substances synthesized by granulosa cells are capable of regulating oocyte activity. We have studied the effect of factors synthesized by granulosa cells on tPA activity of denuded oocytes using a co-culture system. The results show that an FSH-dependent factor(s) synthesized by granulosa cells (but not by theca-interstitial cells) is capable of stimulating tPA activity of denuded oocytes. This finding is important for understanding hormonal regulation of oocyte tPA activity by mediators synthesized in granulosa cells.     

Metallacrown-based compartments: selective encapsulation of three isonicotinate anions in non-centrosymmetric solids

Upon crystallization in high yields, metallacrowns form compartments that are capable of asymmetrically encapsulating three isonicotinate guests.     

Site specific self-cleavage of certain assemblies of G-quadruplex

It is demonstrated that certain structural assemblies of G-quadruplex are capable of performing selfcleaving actions in a site specific fashion.     

Applications of novel proton-conducting polymers to hydrogen sensing

Ionic conducting polymer blends capable of supporting proton conduction from −40°C to 40 °C have been developed. These proton-conducting polymer blends have been used to fabricate hydrogen sensors that are capable of operating at room temperature without the need for an external supply of water vapor. Two sensor designs, both potentiostatic, are being investigated: the first uses a gaseous reference source, and the second a solid state palladium hydride reference. These sensors measure accurately the hydrogen concentration to better than 1%, have a response time of less than 6 s and are not adversely affected by most potential poisons.     

Motility of catalytic nanoparticles through self-generated forces

Small-scale synthetic motors capable of generating their own motive forces by exploiting the chemical free energy of their environment represent an important step in developing practical nanomachines. Catalytic particles are capable of generating concentration and other gradients that can be used to self-propel small objects. However, the autonomous movement of catalytic nanoparticles by self-generated forces is a relatively unexplored area in colloid and interfacial chemistry. This paper explores the potential of catalytically self-generated forces for propulsion of small objects through fluids.     

Observation of the formation of supported bilayers by amphiphilic peptidyl-RNA

Amphiphilic peptidyl-RNA conjugates, molecules that mimic natural peptidyl-transfer RNA, are capable of self-assembling on glass substrates as vesicles and supported bilayers.     

Electrochemical activation of chain radical processes by radical organophosphorus cations

It is found that electrochemically generated radical cations of organophosphorus compounds react with substrates that are capable of homolytic cleavage of the element-hydrogen bond via a radical detachment of the hydrogen atom, thus initiating the chain radical addition of the substrates over the double bond of alkenes. The presence of a strong base that is capable of deprotonating intermediate phosphonium salts in electrolyte allows one to set up an electrocatalytic cycle and use organophosphorus compounds in catalytic quantities. The main side reaction in the studied processes is the interaction between radical cations of organophosphorus compounds and olefin which leads to the formation of phosphorylated alkenes.     

Microbial conversion of high-rank coals to methane

Applied Biochemistry and Biotechnology - It has been demonstrated recently that certain bacteria and fungi are capable of directly or indirectly converting low-rank coals into liquid and gaseous...     

Synthesis and DNA-binding properties of dinuclear platinum(II)-amine complexes of 1,7-dicarba-closo-dodecaborane(12)

The first examples of platinum(II)-amine complexes containing a dicarba-closo-dodecaborane(12) (carborane) moiety are described; preliminary in vitro DNA-binding experiments indicate that the complexes are capable of targetting plasmid DNA.     

Real-time monitoring of protein complexes reveals their quaternary organization and dynamics

The dynamics of protein complexes are crucial for their function yet are challenging to study. Here, we present a nanoelectrospray (nESI) mass spectrometry (MS) approach capable of simultaneously providing structural and dynamical information for protein complexes. We investigate the properties of two small heat shock proteins (sHSPs) and find that these proteins exist as dodecamers composed of dimeric building blocks. Moreover, we show that these proteins exchange dimers on the timescale of minutes, with the rate of exchange being strongly temperature dependent. Because these proteins are expressed in the same cellular compartment, we anticipate that this dynamical behavior is crucial to their function in vivo. Furthermore, we propose that the approach used here is applicable to a range of nonequilibrium systems and is capable of providing both structural and dynamical information necessary for functional genomics.     

Thermoset Shape‐Memory Polyurethane with Intrinsic Plasticity Enabled by Transcarbamoylation

Thermoset polymers are known for their superior thermomechanical properties, but the chemical crosslinking typically leads to intractability. This is reflected in the great differences between thermoset and thermoplastic shape‐memory polymers; the former exhibit a robust shape memory but are not capable of redefining the permanent shape. Contrary to current knowledge, we reveal here that a classical thermoset shape‐memory polyurethane is readily capable of permanent reshaping (plasticity) after a topological network rearrangement that is induced by transcarbamoylation. By employing the Jianzhi technique (also known as kirigami), unexpected shape‐shifting versatility was observed for this otherwise classical material. As the essential carbamate moiety in polyurethanes is one of the most common polymer building units, we anticipate that our finding will have significant benefits beyond shape shifting.     

Theoretical studies of the inductive effect - 3. A thereotical scale of field parameters

It is shown that theoretical calculations on simple systems at the ab initio 4-31G level are capable of reproducing inductive field parametersand can be used to extend the scale to substituents whose values are less well established.     

Investigation of heterocyclic quinones XXV. Tautomeric and covalent hydration in the quinazolinequinone series

The tautomeric forms of 2-phenyl-4-hydroxy-8-piperidinoquinazoline-5,6-quinone were determined quantitatively by means of UV spectroscopy. It is shown that quinazolinequinones are not capable of covalent hydration.     

Progress towards metal-free radical alkylations of quinones under mild conditions

A new method for the radical alkylation of quinones is reported. Lewis basic nitrogen additives increase the efficacy of quinone alkylations from carboxylic acids using catalytic AgNO₃ and Selectfluor as a mild oxidant. Electrochemical data suggests that certain Lewis basic additives are capable of directly reducing Selectfluor through a single-electron transfer, presumably via a charge-transfer complex. This process yields intermediates capable of promoting oxidative decarboxylation of alkyl carboxylic acids without an added metal initiator. Using this strategy, we have demonstrated progress towards a metal-free C–H quinone alkylation reaction that proceeds at room temperature under mild conditions.     

Tetrazole derivatives

The formazan named in the title and its corresponding tetrazolium salt were synthesized. It is shown that both of these compounds are capable of cleavage to give two tetrazole fragments. Reaction products involving the ring and exocyclic nitrogen atoms are formed in the methylation of the formazan. The product from the exocyclic nitrogen atom on heating is converted to a leucoverdazyl radical, which is capable of undergoing oxidation to give the 1-(1-methyl-5-tetrasolyl)-3,5-diphenylverdazyl radical.See [1] for communication XII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 266–269, February. 1977.     

Carbanion-accelerated Claisen rearrangements 3. Vicinal quaternary centers

The preparation and Claisen rearrangement of highly substituted allyl vinyl ethers is described. It is demonstrated that the thermal and anionic versions of the Claisen rearrangement are capable of creating vicinal quaternary centers.