Interaction mechanism and binding mode of phycocyanin to lysozyme: Molecular docking and molecular dynamics simulation.

In this study, multispectral analysis and molecular simulations were performed to investigate the interaction mechanism between phycocyanin (PC) and lysozyme (Lys). The interaction was examined using surface plasmon resonance (SPR), and the structural changes were analyzed using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results suggest that the interaction between PC and Lys was primarily driven by electrostatic, hydrophobic, and hydrogen bonding forces. Molecular dynamics (MD) simulation revealed that Lys preferentially binds between the two subunits, alpha (α) and beta (ß), of PC, with residues ASP-13, GLU-106, and GLU-115 on PC and ARG-119, ARG-107, and ARG-98 on Lys being the main contributors to the binding interaction. Additionally, the formation of the PC-Lys complex resulted in increased kinetic and improved thermal stability of PC, which have important implications for PC applications.

Synergistic Effect of Charge Generation and Separation in Epitaxially Grown BiOCl/Bi2S3 Nano-Heterostructure.

Nano-heterostructures are widely used in the field of optoelectronic devices, and an optimal proportion usually exists between the constituents that make up the structures. Investigation on the mechanism underlying the optimal ratio is instructive for fabricating nano-heterostructures with high efficiency. In this work, BiOCl/Bi2S3 type-II nano-heterostructures with different Bi2S3/BiOCl ratios have been prepared via epitaxial growth of Bi2S3 nanorods on BiOCl nanosheets with solvothermal treatment at different sulfuration temperatures (110-180 °C) and their photoelectrochemical (PEC) performances as photoanodes have been studied. Results indicate that the Bi2S3 content increases with the sulfuration temperature. BiOCl/Bi2S3-170 (i.e., sulfurized@170 °C) exhibits the highest PEC performance under visible-light illumination, whereas BiOCl/Bi2S3-180 with the maximum Bi2S3 content shows the highest visible-light absorption, i.e., possessing the best potential for charge generation. Further analysis indicates that the BiOCl/Bi2S3 heterojunction interface is also crucial in determining the PEC performance of the obtained heterostructures by influencing the charge separation process. With increasing Bi2S3 content, the interface area in the BiOCl/Bi2S3 nano-heterostructures increases first and then decreases due to the mechanical fragility of the nanosheet-nanorod structure and the structural instability in the [010] direction of Bi2S3 with higher Bi2S3 content. Therefore, the increasing content of the Bi2S3 does not necessarily correspond to higher heterojunction area. The optimal performance of BiOCl/Bi2S3-170 results from the maximum of the synthetic coordination of the charge generation and separation. This is the first time ever to figure out the detailed explanation of the optimal property in the nano-heterostructures. The result is inspiring in designing high-performance nano-heterostructures from the point of synthesizing morphological mechanically robust heterostructure and structurally stable constituents to reach a high interfacial area, as well as high light-absorption ability.

Controllable synthesis of Cu-Ni core-shell nanoparticles and nanowires with tunable magnetic properties.

Cu seeds were used to direct the epitaxial growth of Ni shell to form Cu-Ni core-shell cubes, tetrahexahedrons and nanowires. The controllable epitaxial growth of Ni shells on Cu cores provided selectively exposed surfaces and morphologies as well as tunable magnetic properties.

Weighted species sensitivity distribution method to derive site-specific quality criteria for copper in Tai Lake, China.

Tai Lake (Ch: Taihu), which is the largest lake in Jiangsu province, China, has been affected by human activities. As part of a concerted effort to improve water quality to protect the integrity of the Tai Lake ecosystem, a water quality criterion (WQC) was developed for copper (Cu) II. The acute WQC was based on 440 values for acute toxicity of Cu to 24 species from 6 phyla, 16 families, and 20 genera. In addition, 255 values for chronic toxicity of Cu to 10 species from 5 phyla, 8 families, and 9 genera were used to derive chronic WQC. Instead of using a traditional approach based species sensitivity distributions (SSD), a weighted species sensitivity distribution (WSSD) approach was used to calculate the cumulative probability based on endemic species to Tai Lake. Acute and chronic WQC developed by use of the WSSD were 5.3 and 3.7 µg Cu/L, respectively. While the WQC values were comparable to those of other countries, there were slight differences due to variability in species composition of different regions. The site-specific criteria indicated that the current standard set for surface water by the Chinese government might not be protective of aquatic organisms in Tai Lake.

Facile synthesis of Cu and Cu@Cu-Ni nanocubes and nanowires in hydrophobic solution in the presence of nickel and chloride ions.

A highly shape selective synthesis of Cu and Cu@Cu-Ni nanocubes and nanowires has been developed by modulating the coordination chemistry of transition metal ions with a trioctylphosphine (TOP)-Cl(-) ligand pair in oleylamine under mild organic solvent conditions. The as-prepared nanocubes have a face-centered cubic (fcc) phase and are covered by six {100} facets, whereas the as-prepared nanowires have a multi-twinned structure and grow along the [110] direction. Both the Ni(2+) and Cl(-) ions, along with TOP, play vital roles in determining the final morphology of the as-prepared nanocrystals (NCs). TOP can be used to selectively generate single-crystal seeds at the initial stage, which then grow into nanocubes in the presence of Cl(-) ions, while the absence of TOP leads to the formation of multi-twined crystal seeds that finally develop into nanowires. Moreover, Ni can be incorporated to form a Cu-Ni alloy shell over a Cu core at higher temperatures in a one-pot process, which makes diamagnetic Cu NCs magnetically responsive and has a significant influence on their optical properties.

The DNA Sequence and Structural Characteristic of The 5'-Nontranscribed Spacer of Silkworm Attacus ricini rDNA.

We have found that the SacII-EcoRI fragment in the nontranscribed spacer (NTS) of silkworm Attacus ricini rDNA is a nuclear scaffold-associated region (SRA) and showed the function as the ARS element in yeast. This paper reports the sequence of this NTS region and the various characteristic potential functional motifs as analyzed by computer. It is 1 025 bp long and AT-Rich. With 9 bent DNA motifs, 10 T-boxes, 5 A-boxes motifs, 13 topoisomerase II as well as 15 ARS consensus sequences. In addition, there are several dozens of inverted repeats and ATTA/TAAT, ATTTA/TAAAT, ATATTT/AAATAT motifs commonly believed to be the binding sites of many homeodomain proteins. These motifs, concentrated in the SAR region, may play very important role in the regulation of gene transcription and replication at the chromatin level.