Structure-based virtual screening (SBVS) is a widely used method in silico drug discovery. It necessitates a receptor structure or binding site to predict the binding pose and fitness of a ligand. Therefore, the performance of the SBVS is affected by the protein conformation. The most frequently used method in SBVS is the protein-ligand docking program, which utilizes atomic distance-based scoring functions. Hence, they are highly prone to sensitivity towards variation in receptor structure, and it is reported that the conformational change significantly drops the performance of the docking program. To address the problem, we have introduced a novel program of SBVS, named PL-PatchSurfer. This program makes use of molecular surface patches and the Zernike descriptor. The surfaces of the pocket and ligand are segmented into several patches by the program. These patches are then mapped with physico-chemical properties such as shape and electrostatic potential before being converted into the Zernike descriptor, which is rotationally invariant. A complementarity between the protein and the ligand is assessed by comparing the descriptors and geometric distribution of the patches in the molecules. A benchmarking study showed that PL-PatchSurfer2 was able to screen active molecules regardless of the receptor structure change with fast speed. However, the program could not achieve high performance for the targets that the hydrogen bonding feature is important such as nuclear hormone receptors. In this paper, we present the newer version of PL-PatchSurfer, PL-PatchSurfer3, which incorporates two new features: a change in the definition of hydrogen bond complementarity and consideration of visibility that contains curvature information of a patch. Our evaluation demonstrates that the new program outperforms its predecessor and other SBVS methods while retaining its characteristic tolerance to receptor structure changes. Interested individuals can access the program at kiharalab.org/plps3.

Cargo transport within cells is essential to healthy cells, which requires microtubules-based motors, including kinesin. The C-terminal tails (E-hooks) of alpha and beta tubulins of microtubules have been proven to play important roles in interactions between the kinesins and tubulins. Here, we implemented multi-scale computational methods in E-hook-related analyses, including flexibility investigations of E-hooks, binding force calculations at binding interfaces between kinesin and tubulins, electrostatic potential calculations on the surface of kinesin and tubulins. Our results show that E-hooks have several functions during the binding process: E-hooks utilize their own high flexibilities to increase the chances of reaching a kinesin; E-hooks help tubulins to be more attractive to kinesin. Besides, we also observed the differences between alpha and beta tubulins: beta tubulin shows a higher flexibility than alpha tubulin; beta tubulin generates stronger attractive forces (about twice the strengths) to kinesin at different distances, no matter with E-hooks in the structure or not. Those facts may indicate that compared to alpha tubulin, beta tubulin contributes more to attracting and catching a kinesin to microtubule. Overall, this work sheds the light on microtubule studies, which will also benefit the treatments of neurodegenerative diseases, cancer treatments, and preventions in the future.

Extracellular vesicles (EVs) have emerged as important targets in biological and medical studies because they are involved in diverse human diseases and bacterial pathogenesis. Although antibodies targeting the surface biomarkers are widely used to detect EVs, peptide-based curvature sensors are currently attracting an attention as a novel tool for marker-free EV detection techniques. We have previously created a curvature-sensing peptide, FAAV and applied it to develop a simple and rapid method for detection of bacterial EVs in cultured media. The method utilized the fluorescence/Förster resonance energy transfer (FRET) phenomenon to achieve the high sensitivity to changes in the EV amount. In the present study, to develop a practical and easy-to-use approach that can detect bacterial EVs by peptides alone, we designed novel curvature-sensing peptides, N-terminus-substituted FAAV (nFAAV) peptides. The nFAAV peptides exerted higher α-helix-stabilizing effects than FAAV upon binding to vesicles while maintaining a random coil structure in aqueous solution. One of the nFAAV peptides showed a superior binding affinity for bacterial EVs and detected changes in the EV amount with 5-fold higher sensitivity than FAAV even in the presence of the EV-secretory bacterial cells. We named nFAAV5, which exhibited the high ability to detect bacterial EVs, as an EV-sensing peptide. Our finding is that the coil-α-helix structural transition of the nFAAV peptides serve as a key structural factor for highly sensitive detection of bacterial EVs.

As DNA origami applications in biomedicine are expanding, more knowledge is needed to assess these structures\' interaction with biological systems. Here, uptake and penetration in cell and cell spheroid tissue models (CSTMs) are studied to elucidate whether differences in internal structure can be a factor in the efficacy of DNA-origami-based delivery. Two structures bearing largely similar features in terms of both geometry and molecular weight, but with different internal designs-being either compact, lattice-based origami or following an open, wireframe design-are designed. In CSTMs, wireframe rods are able to penetrate deeper than close-packed rods. Moreover, doxorubicin-loaded wireframe rods show a higher cytotoxicity in CSTMs. These results can be explained by differences in structural mechanics, local deformability, local material density, and accessibility to cell receptors between these two DNA origami design paradigms. In particular, it is suggested that the main reason for the difference in penetration dynamic arises from differences in interaction with scavenger receptors where lattice-based structures appear to be internalized to a higher degree than polygonal structures of the same size and shape. It is thus argued that the choice of structural design method constitutes a crucial parameter for the application of DNA origami in drug delivery.

Classic and conventional procedures in molecular cloning are inherent compositions in modern molecular biological experiments and are frequently involved in daily laboratory activities. They take up the majority of the total time input in spite of the availability of well-designed specialized commercial kits. A similar situation is also in the field of biotechnology. Fortunately, microwave/ultrasonic irradiation has been found to be capable of speeding up these processes, such as proteolysis in sample preparation for proteomics research, and digestion, ligation, (de)phosphorylation of DNA with the corresponding enzymes, even the introduction of DNA samples to recipient cells, and biotransformation (e.g., the production of biodiesel). Microwave/ultrasonic irradiation, when used solely or in combination with other existing operations, makes it possible to finish these time-consuming processes in as short as 1 min with comparable or even improved efficiency, and there is no need of reagent upgradation. The adoption of irradiation is ideal because it eliminates any possible side effects of the chemicals used as performance enhancer(s) that will inevitably make the system more complicated at least. More notably, the needed irradiation in the laboratory can be generated by a common microwave oven or ultrasonic cleaner. Taken together, microwave/ultrasonic irradiation provides an accessible method to make the procedures mentioned above time- and cost- efficient. In this article, we reviewed the relevant literature and discussed the experiment and mechanism details.