Targeting PirAvp and PirBvp Toxins of Vibrio parahaemolyticus with Oilseed Peptides: An In Silico Approach

Acute hepatopancreatic necrosis disease (AHPND), caused by PirAvp- and PirBvp-releasing Vibrio parahaemolyticus strains, has resulted in massive mortality in shrimp aquaculture. Excessive use of antibiotics for AHPND management has led to antibiotic resistance, highlighting the urgency to search for alternatives. Using an in silico approach, we aimed to discover PirAvp/PirBvp-binding peptides from oilseed meals as alternatives to antibiotics. To search for peptides that remain intact in the shrimp digestive tract, and therefore would be available for toxin binding, we focused on peptides released from tryptic hydrolysis of 37 major proteins from seeds of hemp, pumpkin, rape, sesame, and sunflower. This yielded 809 peptides. Further screening led to 24 peptides predicted as being non-toxic to shrimp, fish, and humans, with thermal stability and low water solubility. Molecular docking on the 24 peptides revealed six dual-target peptides capable of binding to key regions responsible for complex formation on both PirAvp and PirBvp. The peptides (ISYVVQGMGISGR, LTFVVHGHALMGK, QSLGVPPQLGNACNLDNLDVLQPTETIK, ISTINSQTLPILSQLR, PQFLVGASSILR, and VQVVNHMGQK) are 1139–2977 Da in mass and 10–28 residues in length. Such peptides are potential candidates for the future development of peptide-based anti-AHPND agents which potentially mitigate V. parahaemolyticus pathogenesis by intercepting PirAvp/PirBvp complex formation.

Kinetic Modeling of the Formation of Peptide Nanoparticles by Tryptic Hydrolysis of Β-Casein

Peptide nanoparticles obtained by the enzymatic hydrolysis of proteins are new biocompatible nontoxic systems for the transport of biologically active compounds. The formation of peptide nanoparticles from -casein during its controlled hydrolysis by trypsin was modeled by the methods of chemical kinetics. The product of the time of nanoparticle formation (tmax) by the enzyme concentration (E0) was analyzed in different kinetic models. The dependence of tmax∙E0 on the enzyme concentration was used to estimate the contribution of the enzymatic and non-enzymatic stages to the formation of nanoparticles.

Thermal heliox proteome. High-temperature heliox does not cause destruction of human respiratory system cells

Aim. Conducting a pilot study to assess the effect of thermal heliox on the state of the respiratory tract by studying of the exhaled breath condensate protein composition before the thermal heliox procedure, immediately after and after three hours of relaxation Materials and methods. A comparative study of the exhaled breath condensates (EBC) protein composition of five non-smoking healthy donors was carried out. The EBC was taken before the respiratory procedure, immediately after a 20-minute inhalation by mixture of He/O2 gases (70/30) heated to 70C and 3 hours later. The protein composition was determined by chromatography-mass spectrometric analysis after selective tryptic hydrolysis. The results were processed using the Mascot program and the UniProt database. Results. After the heliox procedure, the volume of the collected condensate (11.5 ml) decreases by an average of 32% and is practically restored after three hours of relaxation. Most proteins were consistent for all samples, regardless of the thermal heliox procedure. These are keratins, several proteins of the immune system (immunoglobulins, compliment proteins), tubulin. In samples after thermal heliox, the appearance of small amounts of additional proteins is observed. These are proteins of muscle metabolism (actin and calmodulin), fibrinogen, traces of hemoglobin, apolipoprotein, type B creatine kinase. After three hours of relaxation, tubulin disappears in the EBC. Conclusion. Most exhaled proteins are the same before, after the procedure, and for three hours of relaxation. The results obtained demonstrate the relative safety of the use of high temperature heliox as a therapeutic agent.