Recombinant Peptide Research Articles

Expression and characterization of the new antimicrobial peptide AP138L-arg26 anti Staphylococcus aureus

The low activity and yield of antimicrobial peptides (AMPs) are pressing problems. The improvement of activity and yield through modification and heterologous expression, a potential way to solve the problem, is a research hot-pot. In this work, a new plectasin-derived variant L-type AP138 (AP138L-arg26) was constructed for the study of recombination expression and druggablity. As a result, the total protein concentration of AP138L-arg26 was 3.1 mg/mL in Pichia pastoris X-33 supernatant after 5 days of induction expression in a 5-L fermenter. The recombinant peptide AP138L-arg26 has potential antibacterial activity against selected standard and clinical Gram-positive bacteria (G+, minimum inhibitory concentration (MIC) 2–16 µg/mL) and high stability under different conditions (temperature, pH, ion concentration) and 2 × MIC of AP138L-arg26 could rapidly kill Staphylococcus aureus (S. aureus) (> 99.99%) within 1.5 h. It showed a high safety in vivo and in vivo and a long post-antibiotic effect (PAE, 1.91 h) compared with vancomycin (1.2 h). Furthermore, the bactericidal mechanism was revealed from two dimensions related to its disruption of the cell membrane resulting in intracellular potassium leakage (2.5-fold higher than control), and an increase in intracellular adenosine triphosphate (ATP), and reactive oxygen species (ROS), the decrease of lactate dehydrogenase (LDH) and further intervening metabolism in S. aureus. These results indicate that AP138L-arg26 as a new peptide candidate could be used for more in-depth development in the future.Key points• The AP138L-arg26 was expressed in the P. pastoris expression system with high yield• The AP138 L-arg26 showed high stability and safety in vitro and in vivo• The AP138L-arg26 killed S. aureus by affecting cell membranes and metabolism

Efficacy of recombinant human brain natriuretic peptide as an adjuvant therapy for severe heart failure, and its impact on oxidative stress and quality of life in patients

Purpose: To evaluate the efficacy of recombinant human brain natriuretic peptide as an adjuvant therapy for severe heart failure, and its effect on oxidative stress and quality of life in patients.
 Methods: The study was conducted on 100 patients with severe heart failure who met the screening criteria for this study. They were evenly but randomly divided into two groups. Patients in the control group were given routine treatment (diuretics and cardiac stimulants) for severe heart failure, while the study group received recombinant human brain natriuretic peptide adjuvant therapy in addition to the treatment administered to the control group. Cardiac function, heart rate, oxidative stress indicators, quality of life levels, and adverse drug reactions during treatment were compared before and after treatment.
 Results: After the intervention, the NT-proBNP level in the study group was significantly lower than in the control group while LVEF level was significantly higher than in the control group (p < 0.05). Compared with the control group, the study group showed a significant decrease in heart rate (p < 0.05). The MDA level of the study group was significantly lower than that of the control group while the SOD and GSH-PX levels were significantly higher than those of the control group (p < 0.05). In addition, the GQOLI-74 score of the study group was significantly higher than that of the control group (p < 0.05). Furthermore, there was no statistically significant difference in incidence of adverse reaction between control and study groups (14.0 and 16.0 %, respectively, p < 0.05).
 Conclusion: Recombinant human brain natriuretic peptide has a significant therapeutic effect on severe heart failure, thus improving patients' cardiac function, alleviating their oxidative stress state and enhancing their quality of life, and is also safe.

Production of functional recombinant roseltide rT1 antimicrobial peptide in tobacco plants

Plant-derived peptides represent a promising group of natural compounds with broad industrial and pharmaceutical applications. Low-efficiency production level is the major obstacle to the commercial production of such bioactive peptides. Today, recombinant techniques have been developed for fast and cost-effective production of high-quality peptides for various applications in the chemical and food industries. The roseltide rT1 is a plant peptide with different antimicrobial properties and therapeutic applications in the prevention and treatment of inflammatory lung diseases by inhibiting human neutrophil elastases. Here, we report the expression of functional recombinant roseltide rT1 peptide in tobacco plants. Transgenic plants were generated by the Agrobacterium-mediated transformation method followed by molecular analysis of transgenic plants to demonstrate successful integration and expression of recombinant rT1 peptide. Protein extracts of transgenic plants expressing a single-copy rT1 gene showed efficient antimicrobial properties as verified by growth inhibition of different bacterial strains. Our results illustrate that plant-derived recombinant rT1 peptide is a promising alternative for rapid and cost-effective production of this important antimicrobial peptide for application in therapeutic and food industries.

Transient inhibition of 53BP1 increases the frequency of targeted integration in human hematopoietic stem and progenitor cells

Genome editing by homology directed repair (HDR) is leveraged to precisely modify the genome of therapeutically relevant hematopoietic stem and progenitor cells (HSPCs). Here, we present a new approach to increasing the frequency of HDR in human HSPCs by the delivery of an inhibitor of 53BP1 (named “i53”) as a recombinant peptide. We show that the use of i53 peptide effectively increases the frequency of HDR-mediated genome editing at a variety of therapeutically relevant loci in HSPCs as well as other primary human cell types. We show that incorporating the use of i53 recombinant protein allows high frequencies of HDR while lowering the amounts of AAV6 needed by 8-fold. HDR edited HSPCs were capable of long-term and bi-lineage hematopoietic reconstitution in NSG mice, suggesting that i53 recombinant protein might be safely integrated into the standard CRISPR/AAV6-mediated genome editing protocol to gain greater numbers of edited cells for transplantation of clinically meaningful cell populations.

Effect of recombinant human brain natriuretic peptide combined with sacubitril and valsartan sodium tablets on the condition of patients with coronary atherosclerotic heart failure

Coronary atherosclerotic heart failure (CAHF) is a common clinical cardiovascular disease that seriously endangers human health. Combination of recombinant human brain natriuretic peptide and sacubitril-valsartan sodium tablets (rhBNP-SV) may have a positive effect on CAHF patients. However, there have been few research on this. In this study, 120 patients with CAHF were collected, 30 of them were used as control group and 90 patients were randomly divided into sacubitril-valsartan sodium tablet group, rhBNP group and combination group. The cardiac function-related indicators and serum mitochondrial coupling factor 6, ACE and others were examined. The levels of various cardiac function indexes in CAHF patients showed an upward trend and the increase was the most obvious in combination group. Patients in combination group had the longest walking distance within 6 minutes. Levels of the four groups of patients showed a downward trend and the intervention of rhBNP-VS showed the most significant decrease. Proportion of IFN-γ-positive lymphocytes in the total T lymphocytes gradually decreased with different interventions. Under rhBNP-SV intervention, ACE level in patients was significantly inhibited. The treatment of rhBNP-SV improved the exercise capacity of patients, reduced inflammatory response, and regulated ACE expression in patients with CAHF. Furthermore, it reduced the degree of vascular endothelial injury, inhibited the development of the disease, and ultimately enhanced the therapeutic effect to a large extent.

Effect of recombinant human brain natriuretic peptide on efficacy, hemodynamics and NT-proBNP in elderly patients with heart failure.

To investigate the effects of recombinant human brain natriuretic peptide (rhBNP) on efficacy, hemodynamics, and N-terminal pro-brain natriuretic peptide (NT-proBNP) in elderly patients with heart failure (HF). In this retrospective analysis, the clinical data of 112 HF patients who visited the First Affiliated Hospital of Anhui University of Chinese Medicine between March 2019 and October 2022 were analyzed. On the basis of standard HF treatment, 52 patients additionally treated with milrinone intravenous were set as the control group (Con) and 60 patients with rhBNP were set as the observation group (Obs). The therapeutic efficacy and pre- and post-treatment echocardiographic indexes, NT-proBNP and hemodynamics were recorded and compared, and the adverse drug reactions and quality of life scores after treatment were counted. The Obs group showed a markedly higher post-treatment overall response rate than the Con (P=0.002). Besides, more obvious improvement of NT-proBNP and hemodynamic indexes were determined in the Obs group compared to the Con (P=0.000). Evidently ameliorated left ventricular ejection fraction (LVEF), left ventricular end-diastolic dimension (LVEDD) and left ventricular end-systolic diameter (LVESD) were observed in both groups after treatment, with more pronounced improvement in the Obs group (all P=0.000). The Obs group also exhibited an evidently lower incidence of adverse reactions and a better quality of life than the Con after treatment (P=0.000). rhBNP can effectively improve the cardiac function and hemodynamics in elderly HF patients, with high safety and few adverse reactions.

Production of recombinant DNA fragmentation factor 40 in fusion to an antimicrobial peptide from spider venom and evaluation of its cytotoxic effects.

DNA fragmentation factor 40 (DFF40) as an apoptotic molecule can represent a novel approach to cancer treatment. Lycosin-I (LYC-I), a peptide derived from spider venom, was considered for the targeted delivery of DFF40 to cancer cells. This study attempted to produce soluble DFF40-LYC-I and evaluate its selective lethal effects on HeLa cells. pTWINl vector was used to produce LYC-I and DFF40-LYC-I in E. coli BL21 (DE3) fused to inteins 1 and 2. IPTG concentration and incubation temperature were optimized to achieve the highest level of soluble product. To remove inteins 1 and 2 from the recombinant peptide or protein, pH shift and dithiothreitol were used for a 24-h incubation period at room temperature, respectively. MTT assay was performed to assess the biological effects of these bio-molecules on HeLa and HUVEC cell lines. LYC-I and DFF40-LYC-I were detected in SDS-PAGE with bands of approximately 57 and 97 kDa, respectively. Furthermore, the 3 and 43 kDa bands showed the purified molecules. The IC50 value of DFF40-LYC-I and DFF40 was determined as 6.6 and 17.03 μg/mL for HeLa, respectively. LYC-I had no cytotoxic effects on both cell lines, even at high concentrations. A new fusion protein with targeted cancer treatment potential was produced for the first time by LYC-I with a safe profile on normal cells. This fusion protein exhibited higher cytotoxic effects in cancer cells compared to normal cells. However, additional investigations are required to determine the apoptosis induction and evaluate selective toxicity against other cancer and normal cell lines.

Antimicrobial Activity of TP4 Recombinant Peptide Alone and in Combination With ZnO NPs on Foodborne Bacteria: Potential as a Milk Preservative

Bacterial resistance, including resistant foodborne pathogenic bacteria, is developing daily, thus becoming a growing public health concern worldwide. Antimicrobial peptides (AMPs) such as tilapia piscidin 4 (TP4) are a class of small peptides widely present in nature that are promising antimicrobial agents that could potentially be considered food preservatives. This study is aimed at investigating the effect of TP4 alone and in combination with zinc oxide nanoparticles (ZnO NPs) on foodborne bacteria in milk. First, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of TP4 and its combination with ZnO NPs (synergistic effect) were measured against four standard foodborne bacteria using the microdilution and checkerboard methods, respectively. According to the results, TP4 showed a high antibacterial effect against four tested strains. Also, TP4 combination with ZnO NPs showed a relative synergistic effect against three tested strains. Then, a time‐kill assay was performed to evaluate the antibacterial effect of TP4 over time on selected bacteria. The results showed that within 24 h, a TP4 concentration of ≥1 × MIC prevented the growth of Gram‐negative and Gram‐positive bacteria. The microbial load of pasteurized and raw milk was also associated with population reduction against the 2 × MIC concentration of TP4. To evaluate the cytotoxicity of TP4, the 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) analysis was performed on the human embryonic kidney‐293 (HEK‐293) cell line and the half‐maximal inhibitory concentration (IC50) was evaluated as 71.61 μg/mL, indicating the nontoxicity of this peptide. Finally, the results showed that TP4 peptide reduces the microbial load of milk, and due to its safety, it can be used as a food preservative.

Lyophilized recombinant human brain natriuretic peptide: A promising therapy in patients with chronic heart failure.

Lyophilized recombinant brain natriuretic peptide (BNP) is an exogenous peptide synthesized by artificial recombination technology, with a similar structure and similar physiological effects with the endogenous natriuretic peptide secreted by the human body. It's main mechanism of action is to increase cyclic guanosine monophosphate by binding with its corresponding receptor in the body, regulating, thus, the imbalance of the vascular system and cardiac hemodynamics, improving the heart's pumping capacity, and inhibiting sympathetic excitability and myocardial remodeling. Moreover, it can promote mitochondrial metabolism and enhance the use of adenosine triphosphate in cardiomyocytes. In the present study, 102 chronic heart failure (HF) patients were randomly assigned to a control and an observation group consisting of 51 patients each. Patients of the control group were treated with standard HF therapy for 3 d including oral metoprolol tartrate tablets, spironolactone, and olmesartanate while patients of the observation group were administered the recombinant human BNP injection for the same time-period, plus the standard HF therapy. The recombinant human BNP group (observation group) demonstrated better physical, emotional, social, and economic scores, as well as cardiac and inflammatory biomarkers such as serum hypersensitive C-reactive protein, N-terminal pro BNP and troponin I levels, compared to the control group. Moreover, cardiac function was also improved, as left ventricular ejection fraction and stroke volume were significantly higher in the observation group than in the control group. Interestingly, adverse reactions were not different between the 2 groups. However, these results are not generalizable and the need of large multicenter randomized controlled trials examining the safety and efficacy of recombinant human BNP in HF patients is of major importance.

Expression, purification, and activity of novel allergen Tyr p 31 from Tyrophagus putrescentiae

Allergen component products, such as recombinant proteins and epitope peptides of allergic components, are used as an adjunct to allergen-specific immunotherapy. We characterized a novel allergen, Tyr p 31, from Tyrophagus putrescentiae, a common allergenic mite. T. putrescentiae total RNA was amplified to Tyr p 31-encoding cDNA, which was inserted into pET28a(+). pET28a(+)-Tyr p 31 was then transformed into Rosetta 2 (DE3) pLysS cells and expressed under isopropyl β-D-thiogalactoside induction. Next, we visualized Tyr p 31 through sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting based on its theoretical molecular weight. Recombinant Tyr p 31 (rTyr p 31) was purified, and its secondary structure was noted to comprise α-helices, antiparallel coils, β-turns, parallel coils, and random coils. Our enzyme-linked immunosorbent assay and Western blotting results for T. putrescentiae–positive sera from children with allergic disorders demonstrated rTyr p 31-specific IgE-positivity rates of 72.41 % and 85.7 %, respectively. In BEAS-2B cells, rTyr p 31 increased IL-6 and IL-8 expression; furthermore, BEAS-2B cells treated with 30 μg/mL rTyr p 31 demonstrated 100 upregulated and 12 downregulated genes. In summary, we identified Tyr p 31, a novel T. putrescentiae allergen component, and noted rTyr p 31 to have a high IgE-binding rate and strong immunogenicity.

Iron-Mediated Electrolysis for Selective Oxidative Decarboxylation of C-Terminal Acids Using Metal-Binding Residue

With the increasing concern of the environmental impact of solid-phase peptide synthesis (SPPS), semi-recombinant processes, in which recombinantly expressed peptides are selectively modified, are of growing interest. The strategies employed for these modifications must overcome the challenges associated with recombinant peptides: selectivity across many functional groups and solubility of the full-length peptide. Electrochemistry is a viable solution to these challenges as it is a mild and tunable process which can operate in both organic and aqueous systems. Herein, a model tetramer with a redox-active residue, tyrosine, is selectively decarboxylated at the C-terminus in an iron-mediated electrolysis. Chemoselectivity is achieved by exploiting the metal-binding property of a C-terminal glutamic acid residue. In the presence of the iron mediator, the tyrosine oxidation pathway is suppressed while the oxidative decarboxylation pathway is favored. Mechanistic controls demonstrate that the glutamic acid, iron, and applied current are all necessary to impart the desired chemoselectivity.

Bomidin attenuates inflammation of periodontal ligament stem cells and periodontitis in mice via inhibiting ferroptosis

AimPeriodontitis is a prevalent oral immunoinflammatory condition that is distinguished by the compromised functionality of periodontal ligament stem cells (PDLSCs). Bomidin, a new recombinant antimicrobial peptide (AMP), exhibits antibacterial properties and modulates immune responses. Nevertheless, the precise anti-inflammatory impact of bomidin in periodontitis has yet to be fully elucidated. Thus, the study aimed to clarified the role of bomidin in modulating inflammation and its underlying mechanisms. MethodsTNF-α was applied to treating PDLSCs for establishing a cell model of periodontitis. Bomidin, RSL3, ML385 and cycloheximide were also used to treat PDLSCs. Transcriptome sequencing, RT-qPCR, western blot, immunofluorescence, immunohistochemistry, Fe2+ detection probe, molecular docking, Co-IP assay, ubiquitination assay and murine models of periodontitis were used. ResultsOur study demonstrated that bomidin effectively suppressed inflammation in PDLSCs stimulated by TNF-α, through down-regulating the MAPK and NF-κB signaling pathways. Furthermore, bomidin exerted inhibitory effects on ferroptosis and activated the Keap1/Nrf2 pathway in the TNF-α group. There is a strong likelihood of bonding bomidin with Keap1 protein, which facilitated the degradation of Keap1 protein via the ubiquitin–proteasome pathway, leading to an enhanced translocation of Nrf2 protein to the nucleus. ConclusionsBomidin can directly bond to Keap1 protein, resulting in the degradation of Keap1 through the ubiquitin–proteasome pathway, thereby further activating the Keap1/Nrf2 pathway. The upregulation of the Keap1/Nrf2 signaling pathway was found to contribute to the suppression of ferroptosis, ultimately alleviating inflammation in treatment of periodontitis.

Immunisation with Neospora caninum subunits rsNcSAG4 and rsNcGRA1 (NcSAG4 and NcGRA1 epitopes construct) in BALB/c mice: the profile of the immune response and controlling the vertical transmission

Neospora caninum is an apicomplexan protozoan that causes neosporosis, which has a high economic impact on cattle herds with no available vaccine. During infection, the secretion of dense granules and the expression of surface antigens play an important role in hosting immunomodulation. However, some epitopes of those antigens are immunogenic, and using these fractions could improve the subunit antigens in vaccine design. This study evaluates the recombinant peptides rsNcGRA1 and rsNcSAG4 derived from NcGRA1 and NcSAG4 native antigens as vaccine candidates produced by a fermentative process in the yeast culture system of Komagataella phaffii strain Km71, confirmed by colony PCR, SDS-PAGE, and western blotting. The assay was conducted in BALB/c mice using the peptides at low (25 μg) and standard (50 μg) dosages in monovalent and combined administrations at three time points with saponin as an adjuvant assessing the immunogenicity by antibodies response and cytokine production. We challenge the females after pregnancy confirmation using 2 × 105 NC-1 tachyzoites previously propagated in Vero cells. We assessed the chronic infection in dams and vertical transmission in the offspring by PCR and histopathology. Mice, especially those immunised with combined peptides and monovalent rsNcGRA1 at a standard dose, controlling the chronic infection in dams with the absence of clinical manifestations, showed an immune response with induction of IgG1, a proper balance between Th1/Th2 cytokines and reduced vertical transmission in the pups. In contrast, dams inoculated with a placebo vaccine showed clinical signs, low-scored brain lesions, augmented chronic infection with 80% positivity, 31% mortality in pups, and 81% vertical transmission. These findings indicate that rsNcGRA1 peptides in monovalent and combined with rsNCSAG4 at standard dose are potential vaccine candidates and improve the protective immune response against neosporosis in mice.

Recombinant bone matrix maintains the graft space, induces vascularized bone regeneration and preserves canine tooth extraction socket structure.

Recombinant bone matrix (RBM) is a newly conceived and engineered porous bone graft granule of average size 600 μm composed of purified recombinant collagen peptide. We sought to examine the behaviour with time of RBM that was grafted in the canine tooth extraction socket. The canine tooth extraction socket of the hemisectioned mandibular third premolar distal root was grafted with RBM granules, whereas the opposite side extraction socket served as non-grafted control. The mandibular samples were harvested at 1, 3 and 6 months of healing and subjected to micro-CT imaging and decalcified paraffin-embedded histology. Separately, the effect of RBM was compared with that of deproteinized cancellous bovine bone (DCBB) and bovine atelocollagen plug (BACP) in the canine tooth extraction model at 3 months of healing. RBM maintained the grafted space in the socket and the gingival connective tissue until new bone was formed within its porous space. The regenerated bone was highly vascularized and continued to mature, while RBM was completely bioresorbed by 6 months. The buccal and lingual alveolar ridge heights of the RBM-grafted extraction socket was better preserved than those of non-grafted control sockets. The degree of socket preservation by RBM was equivalent to that by DCBB, although their healing mechanisms were different. This study demonstrated that RBM induced controlled active bone regeneration and preserved the extraction socket structure in a canine model. Bioresorbable RBM engineered without animal or human source materials presents a novel bone graft category with robust bone regenerative property.

Cytotoxicity and Radiosensitizing Potentials of Pilosulin-3, a Recombinant Ant Venom, in Breast Cancer Cells.

Venom peptides are promising agents in the development of unconventional anticancer therapeutic agents. This study explored the potential of Pilosulin-3, a recombinant peptide from the venom of the Australian jack jumper ant "Myrmecia pilosula", as a cytotoxic and radiosensitizing agent in MCF-7 and MDA-MB-231 breast cancer (BC) cell lines. Pilosulin-3's cytotoxicity was evaluated across a wide range of concentrations using a proliferation assay. Cell cycle progression and apoptosis were examined at the inhibitory concentration 25% (IC25) and IC50 of Pilosulin-3, both with and without a 4Gy X-ray irradiation dose. Radiosensitivity was assessed at IC25 using the clonogenic survival assay. The study revealed that Pilosulin-3 exerted a concentration-dependent cytotoxic effect, with IC25 and IC50 values of 0.01 and 0.5 µM, respectively. In silico screening indicated high selectivity of Pilosulin-3 peptide, which was predicted to be the most likely anticancer agent (PROB = 0.997) with low hemolytic activity (PROP = 0.176). Although Pilosulin-3 exhibited a significant (p < 0.05) G2/M cell cycle arrest in combination with radiation, there was no discernible effect on apoptosis induction or cell survival following irradiation. In conclusion, Pilosulin-3 proved to be cytotoxic to BC cells and induced a cytostatic effect (G2/M arrest) when combined with radiation. However, it did not enhance the efficacy of cell killing by irradiation. While it holds potential as a cytotoxic agent in breast cancer treatment, its application as a radiosensitizer does not find support in these results.

Evaluation of Osteogenic Potential for Rat Adipose-Derived Stem Cells under Xeno-Free Environment.

This study aimed to develop a novel culture method for rat adipose-derived stem cells (rADSC) and evaluate their osteogenic potential. The rADSC cultured in xeno-free culture medium (XF-rADSCs) or conventional culture medium containing fetal bovine serum (FBS-rADSCs) were combined with micropieces of xeno-free recombinant collagen peptide to form 3-dimensional aggregates (XF-rADSC-CellSaic or FBS-rADSC-CellSaic). Both FBS-rADSC and XF-ADSC in CellSaic exhibited multilineage differentiation potential. Compared to FBS-rADSC-CellSaic, XF-rADSC-CellSaic accelerated and promoted osteogenic differentiation in vitro. When transplanted into rat mandibular congenital bone defects, the osteogenically differentiated XF-rADSC-CellSaic induced regeneration of bone tissue with a highly maturated structure compared to FBS-rADSC-CellSaic. In conclusion, XF-rADSC-CellSaic is a feasible 3-dimensional platform for efficient bone formation.

Vaccination against the HDL receptor of S. japonicum inhibits egg embryonation and prevents fatal hepatic complication in rabbit model.

Schistosomiasis is one of the most important neglected tropical infectious diseases to overcome and the primary cause of its pathogenesis is ectopic maturation of the parasite eggs. Uptake of cholesteryl ester from the host high-density lipoprotein (HDL) is a key in this process in Schistosoma japonicum and CD36-related protein (CD36RP) has been identified as the receptor for this reaction. Antibody against the extracellular domain of CD36RP (Ex160) efficiently blocked the HDL cholesteryl ester uptake and the egg embryonation in vitro. However, whether Ex160 immunization could efficiently raise proper antibody responses to sufficiently block HDL cholesteryl ester uptake and the egg embryonation to protect host in vivo is very interesting but unknown. In this study, rabbits were immunized with the recombinant Ex160 peptide (rEx160) to evaluate its anti-pathogenic vaccine potential. Immunization with rEx160 induced consistent anti-Ex160 IgG antibody and significant reduction in development of the liver granulomatosis lesions associated with suppressed intrahepatic maturation of the schistosome eggs. The immunization with rEx160 rescued reduction of serum HDL by the infection without changing its size distribution, being consistent with interference of the HDL lipid uptake by the parasites or their eggs by antibody against Ex160 in in vitro culture. The results demonstrated that vaccination strategy against nutritional supply pathway of the parasite is effective for reducing its pathogenesis.

Recombinant Production of TP4-LYC1, A New Chimeric Peptide with Targeted Cytotoxicity to HeLa Cells.

Tilapia Piscidin 4 (TP4) showed potential anti-tumor effects against various cancer cells. Lycosine-1 (LYC1), is another Antimicrobial Peptides (AMP) from spider venom with targeted penetration to cancer cells without any adverse effects on normal cells. The aim of this study was to produce a soluble recombinant fusion peptide in order to diminish the cytotoxicity of TP4 against normal cells. In order to express of TP4-LYC-1, TP4, and LYC1 in fusion to the inteins1/2 of pTWIN-1 vector, induction condition was optimized to earn soluble peptides. Auto-cleavage induction of inteins1/2 was performed based on IMPACT® manual and their effect on cell viability of HeLa and HUVEC cells was surveyed by MTT assay. The best condition for accessing the most soluble peptide in fusion to the inteins was approximately similar for all three peptides (0.1 mM of IPTG, at 22°C). After the induction of self-cleavage of inteins, a band in 3, 3, and 6 kDa was observed on tricine-SDS-PAGE. The IC50 values of TP4-LYC1 and TP4 against HeLa cells were calculated as 0.83, and 2.75 μM, respectively. In the present study, a novel chimeric peptide, TP4-LYC1, was successfully produced. This fusion protein can act as a safe bio-molecule with potent cytotoxic effects against cancer cells, but the penetration ability and determination of cell death mechanism must be performed in order to have more precise view on the apoptosis induction of this recombinant peptide.

Impact of recombinant human brain natriuretic peptide on emergency dialysis and prognosis in end-stage renal disease patients with type 4 cardiorenal syndrome

Recombinant human brain natriuretic peptide (rhBNP) effects on type 4 cardiorenal syndrome (CRS) and adverse events such as heart failure rehospitalization and all-cause mortality have not been assessed in large-scale research. This study evaluated the impact of rhBNP on emergency dialysis and prognosis in end-stage renal disease (ESRD) patients with type 4 CRS, and the risk factors of emergency dialysis. This retrospective cohort study included patients with type 4 CRS and ESRD admitted for decompensated heart failure between January 2016 and December 2021. Patients were divided into the rhBNP and non-rhBNP cohorts, according to whether they were prescribed rhBNP. The primary outcomes were emergency dialysis at first admission and cardiovascular events within a month after discharge. A total of 77 patients were included in the rhBNP cohort (49 males and 28 females, median age 67) and 79 in the non-rhBNP cohort (47 males and 32 females, median age 68). After adjusting for age, residual renal function, and primary diseases, Cox regression analysis showed that rhBNP was associated with emergency dialysis (HR = 0.633, 95% CI 0.420–0.953) and cardiovascular events (HR = 0.410, 95% CI 0.159–0.958). In addition, multivariate logistic regression analysis showed that estimated glomerular filtration rate (eGFR) (OR = 0.782, 95% CI 0.667–0.917, P = 0.002) and procalcitonin (PCT) levels (OR = 1.788, 95% CI 1.193–2.680, P = 0.005) at the first visit were independent risk factors for emergency dialysis while using rhBNP was a protective factor for emergency dialysis (OR = 0.195, 95% CI 0.084–0.451, P < 0.001). This study suggests that RhBNP can improve cardiac function and reduce the occurrence of emergency dialysis and cardiovascular events in ESRD patients with type 4 CRS.

Development of an Algorithm for Identification of N-terminal Acetyltransferases and Verification of Their Functional Activity

N-terminal acetyltransferases (NATs) of bacteria acetylate the alpha-amino group in amino acids and proteins, participate in the biosynthesis of lantibiotics, and inactivate a number of antibiotics. NATs are used in biotechnology for targeted acetylation of recombinant proteins and peptides. In this regard, the search for NATs that differ in terms of substrate specificity and are also capable of functioning in the reaction at elevated temperatures, a wide pH range, etc., seems relevant. In this work, we develop specific characteristics and a search algorithm for the identification of N-terminal acetyltransferases using the Thermus thermophilus thermophilic bacterium as an example. Out of 14 Abs annotated in the genome, we selected six «putative» NATs. Some of the genes encoding the selected NATs were successfully cloned, generated, and purified from E. coli cells. The specific enzymatic activity of a number of enzymes was confirmed.