Identification of yttrium oxide-specific peptides for future recycling of rare earth elements from electronic scrap

Yttrium is a heavy rare earth element (REE) that acquires remarkable characteristics when it is in oxide form and doped with other REEs. Owing to these characteristics Y2 O3 can be used in the manufacture of several products. However, a supply deficit of this mineral is expected in the coming years, contributing to its price fluctuation. Thus, developing an efficient, cost-effective, and eco-friendly process to recover Y2 O3 from secondary sources has become necessary. In this study, we used phage surface display to screen peptides with high specificity for Y2 O3 particles. After three rounds of enrichment, a phage expressing the peptide TRTGCHVPRCNTLS (DM39) from the random pVIII phage peptide library Cys4 was found to bind specifically to Y2 O3 , being 531.6-fold more efficient than the wild-type phage. The phage DM39 contains two arginines in the polar side chains, which may have contributed to the interaction between the mineral targets. Immunofluorescence assays identified that the peptide's affinity was strong for Y2 O3 and negligible to LaPO4 :Ce3+ ,Tb3+ . The identification of a peptide with high specificity and affinity for Y2 O3 provides a potentially new strategic approach to recycle this type of material from secondary sources, especially from electronic scrap.

Mimotopes for Mycotoxins Diagnosis Based on Random Peptides or Recombinant Antibodies from Phage Library

Mycotoxins, the small size secondary metabolites of fungi, have posed a threat to the safety of medicine, food and public health. Therefore, it is essential to create sensitive and effective determination of mycotoxins. Based on the special affinity between antibody and antigen, immunoassay has been proved to be a powerful technology for the detection of small analytes. However, the tedious preparation and instability of conventional antibodies restrict its application on easy and fast mycotoxins detection. By virtue of simplicity, ease of use, and lower cost, phage display library provides novel choices for antibodies or hapten conjugates, and lead random peptide or recombinant antibody to becoming the promising and environmental friendly immune-reagents in the next generation of immunoassays. This review briefly describes the latest developments on mycotoxins detection using M13 phage display, mainly focusing on the recent applications of phage display technology employed in mycotoxins detection, including the introduction of phage and phage display, the types of phage displayed peptide/recombinant antibody library, random peptides/recombinant antibodies-based immunoassays, as well as simultaneous determination of multiple mycotoxins.

α-Helical Antimicrobial Peptide Encapsulation and Release from Boron Nitride Nanotubes: A Computational Study

Introduction

Antimicrobial peptides are potential therapeutics as anti-bacteria, anti-viruses, anti-fungi, or anticancers. However, they suffer from a short half-life and drug resistance which limit their long-term clinical usage.

Methods

Herein, we captured the encapsulation of antimicrobial peptide HA-FD-13 into boron nitride nanotube (BNNT) (20,20) and its release due to subsequent insertion of BNNT (14,14) with molecular dynamics simulation.

Results

The peptide-BNNT (20,20) van der Waals (vdW) interaction energy decreased to −270 kcal·mol⁻¹ at the end of the simulation (15 ns). However, during the period of 0.2–1.8 ns, when half of the peptide was inside the nanotube, the encapsulation was paused due to an energy barrier in the vicinity of BNNT and subsequently the external intervention, such that the self-adjustment of the peptide allowed full insertion. The free energy of the encapsulation process was −200.12 kcal·mol⁻¹, suggesting that the insertion procedure occurred spontaneously.

Discussion

Once the BNNT (14,14) entered into the BNNT (20,20), the peptide was completely released after 83.8 ps. This revealed that the vdW interaction between the BNNT (14,14) and BNNT (20,20) was stronger than between BNNT (20,20) and the peptide; therefore, the BNNT (14,14) could act as a piston pushing the peptide outside the BNNT (20,20). Moreover, the sudden drop in the vdW energy between nanotubes to the value of the −1300 Kcal·mol⁻¹ confirmed the self-insertion of the BNNT (14,14) into the BNNT (20,20) and correspondingly the release of the peptide.

Application of Next Generation Sequencing (NGS) in Phage Displayed Peptide Selection to Support the Identification of Arsenic-Binding Motifs

Next generation sequencing (NGS) in combination with phage surface display (PSD) are powerful tools in the newly equipped molecular biology toolbox for the identification of specific target binding biomolecules. Application of PSD led to the discovery of manifold ligands in clinical and material research. However, limitations of traditional phage display hinder the identification process. Growth-based library biases and target-unrelated peptides often result in the dominance of parasitic sequences and the collapse of library diversity. This study describes the effective enrichment of specific peptide motifs potentially binding to arsenic as proof-of-concept using the combination of PSD and NGS. Arsenic is an environmental toxin, which is applied in various semiconductors as gallium arsenide and selective recovery of this element is crucial for recycling and remediation. The development of biomolecules as specific arsenic-binding sorbents is a new approach for its recovery. Usage of NGS for all biopanning fractions allowed for evaluation of motif enrichment, in-depth insight into the selection process and the discrimination of biopanning artefacts, e.g., the amplification-induced library-wide reduction in hydrophobic amino acid proportion. Application of bioinformatics tools led to the identification of an SxHS and a carboxy-terminal QxQ motif, which are potentially involved in the binding of arsenic. To the best of our knowledge, this is the first report of PSD combined with NGS of all relevant biopanning fractions.

Design, synthesis, and in vitro antitumor activity of a transferrin receptor-targeted peptide-doxorubicin conjugate

In this study, a peptide-drug conjugate was designed and synthesized by connecting a transferrin receptor (TfR)-targeted binding peptide analog BP9a (CAHLHNRS) with doxorubicin (DOX) through N-succinimidyl-3-maleimidopropionate (SMP) as the cross-linker. Confocal laser scanning microscopy results indicated that free DOX mainly accumulated in the nuclei of both TfR overexpressed HepG2 hepatoma cells and L-O2 normal liver cells expressing low level of TfR; most of the BP9a-DOX conjugate displayed cytoplasmic location, and its cellular uptake by HepG2 cells was obviously reduced by TfR blockage test. Nevertheless, the cellular uptake of this conjugate by L-O2 cells was much less than that of free DOX. Meanwhile, the BP9a-DOX conjugate exhibited lower in vitro antiproliferative activity against HepG2 cells than free DOX, but its cytotoxic effect on L-O2 cells was decreased compared with that of free DOX. These results suggest that BP9a could be applied as a potential TfR-targeted peptide vector for selective drug delivery.