Mitigating the Adverse Effects of Polychlorinated Biphenyl Derivatives on Estrogenic Activity via Molecular Modification Techniques

The aim of this paper is to explore the mechanism of the change in oestrogenic activity of PCBs molecules before and after modification by designing new PCBs derivatives in combination with molecular docking techniques through the constructed model of oestrogenic activity of PCBs molecules. We found that the weakened hydrophobic interaction between the hydrophobic amino acid residues and hydrophobic substituents at the binding site of PCB derivatives and human oestrogen receptor alpha (hERα) was the main reason for the weakened binding force and reduced anti-oestrogenic activity. It was consistent with the information that the hydrophobic field displayed by the 3D contour maps in the constructed oestrogen activity CoMSIA model was one of the main influencing force fields. The hydrophobic interaction between PCB derivatives and oestrogen-active receptors was negatively correlated with the average distance between hydrophobic substituents and hydrophobic amino acid residues at the hERα-binding site, and positively correlated with the number of hydrophobic amino acid residues. In other words, the smaller the average distance between the hydrophobic amino acid residues at the binding sites between the two and the more the number of them, and the stronger the oestrogen activity expression degree of PCBS derivative molecules. Therefore, hydrophobic interactions between PCB derivatives and the oestrogen receptor can be reduced by altering the microenvironmental conditions in humans. This reduces the ability of PCB derivatives to bind to the oestrogen receptor and can effectively modulate the risk of residual PCB derivatives to produce oestrogenic activity in humans.

Effects of Altering Heparan Sulfate Proteoglycan Binding and Capsid Hydrophilicity on Retinal Transduction by Adeno-associated Virus

ABSTRACT Adeno-associated viruses (AAVs) have recently emerged as the leading vector for retinal gene therapy. However, AAV vectors that are capable of achieving clinically relevant levels of transgene expression and widespread retinal transduction are still an unmet need. Using rationally designed AAV2-based capsid variants, we investigate the role of capsid hydrophilicity and hydrophobicity as it relates to retinal transduction. We show that hydrophilic, single-amino-acid mutations (V387R, W502H, E530K, L583R) in AAV2 negatively impact retinal transduction when heparan sulfate proteoglycan (HSPG) binding remains intact. Conversely, addition of hydrophobic point mutations to an HSPG binding-deficient capsid (AAV2ΔHS) leads to increased retinal transduction in both mouse and macaque. Our top performing vector, AAV2(4pMut)ΔHS, achieved robust rod and cone photoreceptor (PR) transduction in macaque, especially in the fovea, and demonstrates the ability to spread laterally beyond the borders of the subretinal injection (SRI) bleb. This study both evaluates biophysical properties of AAV capsids that influence retinal transduction and assesses the transduction and tropism of a novel capsid variant in a clinically relevant animal model. IMPORTANCE Rationally guided engineering of AAV capsids aims to create new generations of vectors with enhanced potential for human gene therapy. By applying rational design principles to AAV2-based capsids, we evaluated the influence of hydrophilic and hydrophobic amino acid mutations on retinal transduction as it relates to vector administration route. Through this approach, we identified a largely deleterious relationship between hydrophilic amino acid mutations and canonical HSPG binding by AAV2-based capsids. Conversely, the inclusion of hydrophobic amino acid substitutions on an HSPG binding-deficient capsid (AAV2ΔHS) generated a vector capable of robust rod and cone photoreceptor (PR) transduction. This vector AAV2(4pMut)ΔHS also demonstrates a remarkable ability to spread laterally beyond the initial subretinal injection (SRI) bleb, making it an ideal candidate for the treatment of retinal diseases that require a large area of transduction.

Guanidine-rich helical polypeptides bearing hydrophobic amino acid pendants for efficient gene delivery

Guanidine-rich helical polypeptides bearing hydrophobic amino acid pendants displayed high transfection efficiency both in vitro and in vivo and low cytotoxicity toward applications in gene therapy.

Chemical Characteristics and Activity of ACE Inhibitors on Fractionation of Tempeh Koro kratok (Phaseolus lunatus) Peptides

Tempeh is a fermented food that is good for health and has high nutritional value. Koro kratok tempeh is one of tempeh which is made from non-soybean legumes. The fermentation process will convert macromolecular compounds to micromolecules thereby increasing bioavailability and providing functional properties. This study aimed to find out the chemical properties of koro kratok tempeh and the effect of peptide molecular weight of koro kratok tempeh on ACE inhibition activity. The results show that koro kratok seeds contained 20.66% protein which total hydrophobic amino acid was 3.32% (w/w protein). This hydrophobic amino acid was higher than that soybean, indicated that koro kratok (Phaseolus lunatus) has a potential producing ACE peptide inhibitors. The koro kratok seeds had ACE inhibitory activity 19.72%. This activity increased to 84.97% when the seeds were fermented for 48h to become tempeh. Peptide fractionation showed that the smaller the molecular weight of the peptide, the higher the ACE inhibitory activity.

Cellular Uptake and Cytosolic Delivery of a Cyclic Cystine Knot Scaffold

Cyclotides are macrocyclic peptides that have exceptionally stable structures and been reported to penetrate cells, making them promising scaffolds for the delivery of peptide inhibitory sequences to target intracellular proteins. However, their cellular uptake and cytosolic localization have been poorly understood until now, which has limited their therapeutic potential. In this study, the recently developed chloroalkane penetration assay was combined with established assays to characterize the cellular uptake and cytosolic delivery of the prototypic cyclotide, kalata B1. We show that kalata B1 enters the cytosol at low efficiency, but introducing various epitopes, including a single hydrophobic amino acid, into its loop 6 significantly improved its cytosolic delivery. Our results provide a foundation for the further development of a structurally unique class of scaffolds for the delivery of therapeutic cargoes into cells.<br>