Therapeutic Effect of a Newly Isolated Lytic Bacteriophage against Multi-Drug-Resistant Cutibacterium acnes Infection in Mice

Acne vulgaris, which is mostly associated with the colonization of Cutibacterium acnes (C. acnes), is a common skin inflammatory disease in teenagers. However, over the past few years, the disease has extended beyond childhood to chronically infect approximately 40% of adults. While antibiotics have been used for several decades to treat acne lesions, antibiotic resistance is a growing crisis; thus, finding a new therapeutic target is urgently needed. Studies have shown that phage therapy may be one alternative for treating multi-drug-resistant bacterial infections. In the present study, we successfully isolated a C. acnes phage named TCUCAP1 from the skin of healthy volunteers. Morphological analysis revealed that TCUCAP1 belongs to the family Siphoviridae with an icosahedral head and a non-contractile tail. Genome analysis found that TCUCAP1 is composed of 29,547 bp with a G+C content of 53.83% and 56 predicted open reading frames (ORFs). The ORFs were associated with phage structure, packing, host lysis, DNA metabolism, and additional functions. Phage treatments applied to mice with multi-drug-resistant (MDR) C.-acnes-induced skin inflammation resulted in a significant decrease in inflammatory lesions. In addition, our attempt to formulate the phage into hydroxyethyl cellulose (HEC) cream may provide new antibacterial preparations for human infections. Our results demonstrate that TCUCAP1 displays several features that make it an ideal candidate for the control of C. acnes infections.

Role of backbone strain in de novo design of complex α/β protein structures

We previously elucidated principles for designing ideal proteins with completely consistent local and non-local interactions which have enabled the design of a wide range of new αβ-proteins with four or fewer β-strands. The principles relate local backbone structures to supersecondary-structure packing arrangements of α-helices and β-strands. Here, we test the generality of the principles by employing them to design larger proteins with five- and six- stranded β-sheets flanked by α-helices. The initial designs were monomeric in solution with high thermal stability, and the nuclear magnetic resonance (NMR) structure of one was close to the design model, but for two others the order of strands in the β-sheet was swapped. Investigation into the origins of this strand swapping suggested that the global structures of the design models were more strained than the NMR structures. We incorporated explicit consideration of global backbone strain into the design methodology, and succeeded in designing proteins with the intended unswapped strand arrangements. These results illustrate the value of experimental structure determination in guiding improvement of de novo design, and the importance of consistency between local, supersecondary, and global tertiary interactions in determining protein topology. The augmented set of principles should inform the design of larger functional proteins.

Insights into molecular packing effects on the emission properties of fluorenone-based molecules in the aggregate state

A structure–packing–property relationship study of fluorenone-based molecules indicates that the formation of a three-dimensional molecular packing network is an effective way to suppress molecular motions to achieve AIE properties.

DBU-Catalyzed Rearrangement of Secondary Propargylic Alcohols: An Efficient and Cost-Effective Route to Chalcone Derivatives

A 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed rearrangement of diarylated secondary propargylic alcohols to give α,β-unsaturated carbonyl compounds has been developed. The typical 1,3-transposition of oxy functionality, characteristic of Mayer–Schuster rearrangements, is not observed in this case. A broad substrate scope, functional-group tolerance, operational simplicity, complete atom economy, and excellent yields are among the prominent features of the reaction. Additionally, the photophysical properties and crystal-structure-packing behavior of selected compounds were investigated and found to be of interest.

Poly[di(μ2-2-hydroxypropanoato)cadmium]

The asymmetric unit of the title inorganic–organic salt, poly[di(μ 2 -2-hydroxypropanoato)cadmium], [Cd(C3H5O3)2] n or [Cd(Hlac)2] n (H2lac = 2-hydroxypropanoic acid), comprises of a cadmium cation and two 2-hydroxypropanoate anions. The cadmium cation exhibits a distorted pentagonal–bipyramidal coordination environment defined by the hydroxy and carbonyl O atoms of the 2-hydroxypropanoate anions. The coordination mode leads to the formation of layers extending parallel to (010). O—H...O hydrogen bonding between the hydroxy and carbonyl groups stabilizes the structure packing.

Three polymorphs of 3-(3-phenyl-1H-1,2,4-triazol-5-yl)-2H-1-benzopyran-2-one formed from different solvents

The polymorphic study of 3-(3-phenyl-1H-1,2,4-triazol-5-yl)-2H-1-benzopyran-2-one, C17H11N3O2, was performed due to its potential biological activity and revealed three polymorphic modifications in the triclinic space group P\overline{1}, the monoclinic space group P21 and the orthorhombic space group Pbca. These polymorphs have a one-column layered type of crystal organization. The strongest interactions between the molecules of the studied structures is stacking between π-systems, while N—H...N and C—H...O hydrogen bonds link stacked columns forming layers as a secondary basic structural motif. C—H...π hydrogen bonds were observed between neighbouring layers and their role is the least significant in the formation of the crystal structure. Packing differences between the polymorphic modifications are minor and can be identified only using an analysis based on a comparison of the pairwise interaction energies.

Изменение температуры Дебая при аморфизации однокомпонентного вещества

Based on the nonlinear dependence of the first coordination number versus of the structure-packing factor (kp), a method for calculating of the Debye temperature for the amorphous structure of a monoatomic substance is proposed. By means of the parameters of pairwise Mie-Lennard-Jones potential, the Debye temperatures were calculated for the crystalline and amorphous structures of a number of pure metals, diamond, Si, Ge. Good agreement is obtained with the estimates of other authors. It is shown that at kp = 0.45556 the minimum of the Helmholtz specific free energy is reached, i.e. this packing is the thermodynamically stable amorphous structure. This work was supported by the Russian Foundation for Basic Research (project no. 18-29-11013_mk) and the program no. I.13 of the Presidium of the Russian Academy of Sciences.