Visualization of interactions between siderophore transporters and the energizing protein TonB by native PAGE

Horizontal nondenaturing electrophoresis of proteins in polyacrylamide gels was used to observe specific interactions between membrane proteins. The method was particularly well suited for solubilized transporters of the outer membrane of Gram-negative bacteria, and allowed specific complexes of transporter and the inner-membrane protein TonB to be isolated. We have used this method to investigate the interactions between four different outer-membrane transporters, and the TonB proteins from two different organisms. The results show that a stable complex can be isolated on gels for all the proteins studied, but can depend in some cases of the detergent used for solubilization. Furthermore, we observe cross-species interaction as TonB from a given organism can interact with transporters from another organism.     

An operationally simple,one-pot,convenient synthesis,and in vitro anti-inflammatory activity of some new spirotriazolotriazine derivatives

The wide biological actions of triazolotriazine hybrids, benzene-sulfonamide derivatives, exhibit a good chance of displaying in vitro anti-inflammatory effects. An operationally simple one-pot, three-component, and convenient synthesis method is used toward the synthesis of a series of diverse 2-(2-(4-amino)-1,3,5-triazaspiro-1,4-dien-2-yl) hydrazinyl)-N-(4-sulfamoylphenyl)-2-thioxoacetamides, which generated via reaction of 2-hydrazinyl-N-(4-sulfamoylphenyl)-2-thioxoacetamide, cyanoguanidine, and cyclic/acyclic ketones and were characterized by spectral analysis (IR, Nuclear Magnetic Resonance: ¹H-NMR, ¹³C-NMR, and elemental analysis). The spirotriazolotriazine derivatives are obtained with up to 95% yield, and their structure–activity relationship was discussed. All compounds were tested for in vitro anti-inflammatory potential using the inhibition of RBC hemolysis technique and COX inhibition assay. The results from RBC hemolysis technique demonstrated that almost all evaluated compounds exhibited significant in vitro anti-inflammatory efficacy. More specifically, compounds 7, 8 , and 12 have superior membrane stability over indomethacin as a standard drug. At concentrations of 400, 600, 800, and 1000 μg/mL, compound 12 demonstrated highly significant inhibition of RBC hemolysis with 95.2%, 97.3%, 98.9%, and 99.8%, respectively, compared with indomethacin at the same concentrations (94.5%, 97.3%, 98.5%, and 99.3%, respectively). COX assay indicated that compounds 7, 8, and 12 exhibited excellent COX-2 inhibition percentage (98.51 ± 0.01, 98 ± 0.01, and 98.97 ± 0.06, respectively) at 150 μg/mL using indomethacin (97.3 ± 0.005). Furthermore, an investigation using molecular docking against COX-2 (pdb ID: 5IKT) was used to analyze the anti-inflammatory properties of all studied substances. When compared to indomethacin, molecular docking research showed a strong connection with the intended protein and an elevated docking score. According to in vitro anti-inflammatory action and computational approach, they show promise as a therapeutic candidate for the treatment of inflammatory diseases.     

On approximation of Lie groups by discrete subgroups

A locally compact group G is said to be approximated by discrete subgroups (in the sense of Tôyama) if there is a sequence of discrete subgroups of G that converges to G in the Chabauty topology (or equivalently, in the Vietoris topology). The notion of approximation of Lie groups by discrete subgroups was introduced by Tôyama in Kodai Math. Sem. Rep. 1 (1949) 36–37 and investigated in detail by Kuranishi in Nagoya Math. J. 2 (1951) 63–71. It is known as a theorem of Tôyama that any connected Lie group approximated by discrete subgroups is nilpotent. The converse, in general, does not hold. For example, a connected simply connected nilpotent Lie group is approximated by discrete subgroups if and only if G has a rational structure. On the other hand, if Γ is a discrete uniform subgroup of a connected, simply connected nilpotent Lie group G then G is approximated by discrete subgroups Γ _n containing Γ. The proof of the above result is by induction on the dimension of G, and gives an algorithm for inductively determining Γ _n . The purpose of this paper is to give another proof in which we present an explicit formula for the sequence (Γ _n ) _n?≥?0 in terms of Γ. Several applications are given.     

Singular limit solutions for 2-dimensional elliptic system with sub-quadrtatic convection term

The existence of singular limit solutions are investigated by establishing a new Liouville type theorem for nonlinear elliptic system with sub-quadratic convection term and by using the nonlinear domain decomposition method.     

On Nonlinearly Elastic Membranes under Compression

The classical equations of a nonlinearly elastic plane membrane made of Saint Venant-Kirchhoff material have been justified by Fox, Raoult and Simo (1993) and Pantz (2000). We show that, under compression, the associated minimization problem admits no solution. The proof is based on a result of non-existence of minimizers of non-convex functionals due to Dacorogna and Marcellini (1995). We generalize the application of their result from plane elasticity to three-dimensional plane membranes.