Protein Precipitation Using Ammonium Sulfate

Human and camel cystic echinococcosis - a polyclonal antibody-based sandwich ELISA for its serodiagnosis with molecular identification

Cystic echinococcosis (CE) is an emergent neglected disease affecting human and animals in Egypt with a wide distribution and incidence. This study aimed to evaluate the use of a polyclonal antibody-based sandwich ELISA in the detection of Echinococcus granulosus antigen in human and camel sera. Hydatid cyst protoscoleces antigen (PsAg) was isolated from hydatid cysts collected from naturally infected camel livers and lungs. PsAg was used for immunization of rabbits to raise IgG polyclonal antibodies (IgG PsAb). IgG PsAb were then precipitated, purified using Protein-A Sepharose gel and labeled with horseradish peroxidase enzyme. We assayed the purity of the IgG PsAb, and the two prepared E. granulosus antigens CPsAg from camel cysts and HPsAg from human cysts by Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The resulted protein bands of the prepared CPsAg appeared at different molecular weights: 180, 90, 68, 54, 42 and 22 kDa while, HPsAg shared with it in 4 common bands at 68, 54, 42, and 22 kDa. The purified IgG PsAb had been resolved at two bands at 52 kDa and at 32 kDa. Sandwich ELISA were performed for the detection of circulating E. granulosus antigens in sera of human (n = 183) and camels (n = 190). The purified IgG PsAb showed strong reactivity against E. granulosus infected human and camel samples and no cross reactivity neither with free-healthy negative sera nor with others parasitic diseases (Schistosomiasis, Fascioliasis, Toxoplasmosis, Ancylostomiasis for human samples and Fascioliasis, ticks' infestation, Eimeriosis, Cryptosporidiosis, Nasal myiasis, Toxoplasmosis for camel samples). The sensitivity of the assay was 98.25% (56/57) and 96.9% (31/32) against human and camel samples, respectively. Specificity was 100% in both human and camel samples. Sandwich ELISA detected CE in 33.3% (24/72) and 55.6% (50/90) random human and camel samples, respectively. Indirect ELISA, using CPsAg, was used for detection of antibodies in positive human and camels' sera and detected 96.5% (55/57) and 93.8% (30/32) of human and camel samples, respectively. In our study, Genomic DNA was extracted from protoscoleces fluid of human liver hydatid cysts to identify the Echinococcus sp. isolate based on NADH dehydrogenase subunit 1 (NAD1) gene by Polymerase Chain Reaction (PCR) and the isolate (GenBank: OP785689.1) were identified as E. granulosus sensu lato genotype. In conclusion, Sandwich ELISA technique was found to be a potent and sensitive assay for detection of hydatid antigen in both human and camel samples.

Investigates the ability of plant extracts from Lens culinaris to protect zucchini from the Zucchini yellow mosaic virus (ZYMV)

Evaluate the impact of extracts from the Lens culinaris plant on a number of physiological and biochemical parameters in squash leaves infected with ZYMV in this work. Compared to the untreated leaves, ZYMV infected leaves showed a range of symptoms, such as severe mosaic, size reduction, stunting, and deformation. Analysis of physiological data revealed that L. culinaris extract lectin therapies and viral infections had an impact on metabolism. Protein, carbohydrate, and pigment levels were all lowered by viral infection. However, phenolic compounds, total protein, total carbohydrates, total amino acids, proline, total chlorophyll and peroxidases levels are considerably elevated with all extract therapies. The other biochemical parameters also displayed a variety of changes. Moreover shoot length, number of leaves and number of flowers was significantly increased compared to viral control in all treatments. The L. culinaris extract treatment increases the plant's ZYMV resistance. This is detectable through reduction of the plants treated with lentil lectin pre and post virus inoculation, reduction in disease severity and viral concentration, and percentage of the infected plants has a virus. All findings demonstrate significant metabolic alterations brought by viral infections or L. culinaris extract treatments, and they also suggest that exogenous extract treatments is essential for activating the body's defences against ZYMV infection.

Antifungal, Antimycobacterial, Protease and α‒Amylase Inhibitory Activities of a Novel Serine Bifunctional Protease Inhibitor from Adenanthera pavonina L. Seeds

Antifungal resistance poses a significant challenge to disease management, necessitating the development of novel drugs. Antimicrobial peptides offer potential solutions. This study focused on extraction and characterization of peptides from Adenanthera pavonina seeds with activity against Candida species, Mycobacterium tuberculosis, proteases, and α-amylases. Peptides were extracted in phosphate buffer and heated at 90°C for 10 min to create a peptide rich heated fraction (PRHF). After confirming antimicrobial activity and the presence of peptides, the PRHF underwent ion exchange chromatography, yielding retained and non-retained fractions. These fractions were evaluated for antimicrobial activity and cytotoxicity against murine macrophages. The least toxic and most active fraction underwent reversed-phase chromatography, resulting in ten fractions. These fractions were tested for peptides and antimicrobial activity. The most active fraction was rechromatographed on a reversed-phase column, resulting in two fractions that were assessed for antimicrobial activity. The most active fraction revealed a single band of approximately 6 kDa and was tested for inhibitory effects on proteases and α-amylases. Thermal stability experiments were conducted on the 6 kDa peptide at different temperatures followed by reassessment of antifungal activity and circular dichroism. The 6 kDa peptide inhibited yeasts, M. tuberculosis, human salivary and Tenebrio molitor larvae intestine α-amylases, and proteolytic activity from fungal extracts, and thus named ApPI. Remarkably, ApPI retained antifungal activity and conformation after heating and is primarily composed of α-helices. ApPI is a thermally stable serine protease/α-amylase inhibitor from A. pavonina seeds, offering promise as a foundational molecule for innovative therapeutic agents against fungal infections and tuberculosis.

Glycosylated queuosines in tRNAs optimize translational rate and post-embryonic growth

Transfer RNA (tRNA) modifications are critical for protein synthesis. Queuosine (Q), a 7-deaza-guanosine derivative, is present in tRNA anticodons. In vertebrate tRNAs for Tyr and Asp, Q is further glycosylated with galactose and mannose to generate galQ and manQ, respectively. However, biogenesis and physiological relevance of Q-glycosylation remain poorly understood. Here, we biochemically identified two RNA glycosylases, QTGAL and QTMAN, and successfully reconstituted Q-glycosylation of tRNAs using nucleotide diphosphate sugars. Ribosome profiling of knockout cells revealed that Q-glycosylation slowed down elongation at cognate codons, UAC and GAC (GAU), respectively. We also found that galactosylation of Q suppresses stop codon readthrough. Moreover, protein aggregates increased in cells lacking Q-glycosylation, indicating that Q-glycosylation contributes to proteostasis. Cryo-EM of human ribosome-tRNA complex revealed the molecular basis of codon recognition regulated by Q-glycosylations. Furthermore, zebrafish qtgal and qtman knockout lines displayed shortened body length, implying that Q-glycosylation is required for post-embryonic growth in vertebrates.

Enzymatic degradation and metabolic pathway of phenanthrene by manglicolous filamentous fungus Trichoderma sp. CNSC-2

Manglicolous filamentous fungi release extracellular lignolytic enzymes that can readily degrade polycyclic aromatic hydrocarbons (PAHs). The present study emphasizes the role of the extracellular enzyme in phenanthrene degradation by the manglicolous fungus Trichoderma sp. CNSC-2 isolated from the Indian Sundarban mangrove ecosystem. The removal efficiency reached 64.05 ± 0.75 % in 50 mg l-1 phenanthrene-amended mineral salt medium at pH 5.6 after 10 days of incubation. Phenanthrene removal was optimized at different pH, nutrient sources, and Cu2+ concentrations. The degradation significantly increased to 67.75 ± 4.32 % at pH 6 (P < 0.0001). The addition of Cu2+ (30 mg l-1) increased the degradation to 78.15 ± 0.36 % (P < 0.0001). The validation experiment confirmed the increase in phenanthrene degradation up to 79.9 ± 1.67 % under optimized conditions. The Lac1 and CytP450 genes encoding for extracellular and intracellular enzymes, respectively, were identified. The GC-MS derived phenanthrene degradation metabolites, i.e., phthalic acid, isobutyl 2-pentyl ester derivative, 1, 2 benzene dicarboxylic acid, butyl 2-methyl propyl ester derivative, TMS derivative of benzoic acid and 3,5 dihydroxy benzoic acid determined two possible metabolic pathways. The laccase enzyme activity was higher in the presence of Phe+Cu2+ (P < 0.0001), indicating the enzyme induction potential of PAH and Cu2+ ions. Purified laccase had a molecular weight of 45 kDa and was highly stable at pH 4-6 and temperature 20-50 °C. The enzyme retained 47 %, 87 %, and 63 % of enzyme activity at 30 mg l-1 concentration of Pb2+, Cd2+, and Hg2+. However, laccase activity was induced by 1.37 folds in the presence of 30 mg l-1 Cu2+ concentration. Thus, the study suggests the potential role of Trichoderma sp. CNSC-2 in phenanthrene degradation.

Stability of DNA Origami Nanostructures in Physiological Media: The Role of Molecular Interactions

Programmable, custom-shaped, and nanometer-precise DNA origami nanostructures have rapidly emerged as prospective and versatile tools in bionanotechnology and biomedicine. Despite tremendous progress in their utilization in these fields, essential questions related to their structural stability under physiological conditions remain unanswered. Here, DNA origami stability is explored by strictly focusing on distinct molecular-level interactions. In this regard, the fundamental stabilizing and destabilizing ionic interactions as well as interactions involving various enzymes and other proteins are discussed, and their role in maintaining, modulating, or decreasing the structural integrity and colloidal stability of DNA origami nanostructures is summarized. Additionally, specific issues demanding further investigation are identified. This review - through its specific viewpoint - may serve as a primer for designing new, stable DNA objects and for adapting their use in applications dealing with physiological media.

Nano magnetic-based ELISA and nano magnetic-based latex agglutination test for diagnosis of experimental trichinellosis

Human trichinellosis is a worldwide foodborne public health threat. Detecting circulating antigens of Trichinella spiralis "T. spiralis" allows for an early diagnosis before larval encystation develops in skeletal muscles. For the first time, the present study aimed to formulate an effective nanomagnetic beads based-ELISA and -latex agglutination test (NMB-ELISA and NMB-LAT) to recognize T. spiralis adult worm crude extract antigen (AWCEA) in sera of experimentally infected mice. The study included thirty-eight mice classified into 3 groups; T. spiralis-infected group (GI) which was euthanized 6, 8, 10, 12, 14 days post-infection (dpi), other parasitic infections group (GII) and healthy control group (GIII). Rabbit anti-T. spiralis polyclonal antibodies (pAbs) were utilized to detect AWCEA in serum samples by sandwich ELISA, NMB-ELISA, and NMB-LAT. Using NMB-ELISA, AWCEA was detected in sera collected at 6 and 8 dpi, with a sensitivity of 50% and 75%, respectively, and a specificity of 100%. Whereas, sandwich ELISA and NMB-LAT couldn't detect the antigen at the same time intervals. Both ELISA formats were able to detect the antigen in samples collected at 10, 12, and 14 dpi with a sensitivity of 100% for NMB-ELISA and 25%, 75%, and 100% respectively, for sandwich-ELISA. Yet, NMB-LAT couldn't detect AWCEA until 12 dpi with a sensitivity of 50% and specificity of 75%. In conclusion, NMB-ELISA is a promising sensitive tool for early and specific diagnosis of acute trichinellosis. The use of NMB-LAT could be a helpful screening procedure in field surveys.

Purification, Characterization and Bactericidal Action of Lysozyme, Isolated from Bacillus subtillis BSN314: A Disintegrating Effect of Lysozyme on Gram-Positive and Gram-Negative Bacteria

In the present study, lysozyme was purified by the following multi-step methodology: salt (ammonium sulfate) precipitation, dialysis, and ultrafiltration. The lysozyme potential was measured by enzymatic activity after each purification step. However, after ultrafiltration, the resulting material was considered extra purified. It was concentrated in an ultrafiltration centrifuge tube, and the resulting protein/lysozyme was used to determine its bactericidal potential against five bacterial strains, including three gram-positive (Bacillus subtilis 168, Micrococcus luteus, and Bacillus cereus) and two gram-negative (Salmonella typhimurium and Pseudomonas aeruginosa) strains. The results of ZOI and MIC/MBC showed that lysozyme had a higher antimicrobial activity against gram-positive than gram-negative bacterial strains. The results of the antibacterial activity of lysozyme were compared with those of ciprofloxacin (antibiotic). For this purpose, two indices were applied in the present study: antimicrobial index (AMI) and percent activity index (PAI). It was found that the purified lysozyme had a higher antibacterial activity against Bacillus cereus (AMI/PAI; 1.01/101) and Bacillus subtilis 168 (AMI/PAI; 1.03/103), compared to the antibiotic (ciprofloxacin) used in this study. Atomic force microscopy (AFM) was used to determine the bactericidal action of the lysozyme on the bacterial cell. The purified protein was further processed by gel column chromatography and the eluate was collected, its enzymatic activity was 21.93 U/mL, while the eluate was processed by native-PAGE. By this analysis, the un-denatured protein with enzymatic activity of 40.9 U/mL was obtained. This step shows that the protein (lysozyme) has an even higher enzymatic potential. To determine the specific peptides (in lysozyme) that may cause the bactericidal potential and cell lytic/enzymatic activity, the isolated protein (lysozyme) was further processed by the SDS-PAGE technique. SDS-PAGE analysis revealed different bands with sizes of 34 kDa, 24 kDa, and 10 kDa, respectively. To determine the chemical composition of the peptides, the bands (from SDS-PAGE) were cut, enzymatically digested, desalted, and analyzed by LC-MS (liquid chromatography-mass spectrometry). LC-MS analysis showed that the purified lysozyme had the following composition: the number of proteins in the sample was 56, the number of peptides was 124, and the number of PSMs (peptide spectrum matches) was 309. Among them, two peptides related to lysozyme and bactericidal activities were identified as: A0A1Q9G213 (N-acetylmuramoyl-L-alanine amidase) and A0A1Q9FRD3 (D-alanyl-D-alanine carboxypeptidase). The corresponding protein sequence and nucleic acid sequence were determined by comparison with the database.

Technological interventions in improving the functionality of proteins during processing of meat analogs

Meat analogs have opened a new horizon of opportunities for developing a sustainable alternative for meat and meat products. Proteins are an integral part of meat analogs and their functionalities have been extensively studied to mimic meat-like appearance and texture. Proteins have a vital role in imparting texture, nutritive value, and organoleptic attributes to meat analogs. Processing of suitable proteins from vegetable, mycoproteins, algal, and single-cell protein sources remains a challenge and several technological interventions ranging from the isolation of proteins to the processing of products are required. The present paper reviews and discusses in detail various proteins (soy proteins, wheat gluten, zein, algal proteins, mycoproteins, pulses, potato, oilseeds, pseudo-cereals, and grass) and their suitability for meat analog production. The review also discusses other associated aspects such as processing interventions that can be adapted to improve the functional and textural attributes of proteins in the processing of meat analogs (extrusion, spinning, Couette shear cell, additive manufacturing/3D printing, and freeze structuring). '.

Milk-Gelling Properties of Proteases Extracted from the Fruits of Solanum Elaeagnifolium Cavanilles

There is little information on the milk coagulation process by plant proteases combined with chymosins. This work is aimed at studying the capability of protease enclosed in the ripe fruits of Solanum elaeagnifolium (commonly named trompillo) to form milk gels by itself and in combination with chymosin. For this purpose, proteases were partially purified from trompillo fruits. These proteases had a molecular weight of ~60 kDa, and results suggest cucumisin-like serine proteases, though further studies are needed to confirm this observation. Unlike chymosins, trompillo proteases had high proteolytic activity (PA = 50.23 U_Tyr mg protein⁻¹) and low milk-clotting activity (MCA = 3658.86 SU mL⁻¹). Consequently, the ratio of MCA/PA was lower in trompillo proteases (6.83) than in chymosins (187 to 223). Our result also showed that milk gels formed with trompillo proteases were softer (7.03 mPa s) and had a higher release of whey (31.08%) than the milk gels clotted with chymosin (~10 mPa s and ~4% of syneresis). However, the combination of trompillo proteases with chymosin sped up the gelling process (21 min), improved the firmness of milk gels (12 mPa s), and decreased the whey release from milk curds (3.41%). Therefore, trompillo proteases could be combined with chymosin to improve the cheese yield and change certain cheese features.

Salting-Out of DNA Origami Nanostructures by Ammonium Sulfate

DNA origami technology enables the folding of DNA strands into complex nanoscale shapes whose properties and interactions with molecular species often deviate significantly from that of genomic DNA. Here, we investigate the salting-out of different DNA origami shapes by the kosmotropic salt ammonium sulfate that is routinely employed in protein precipitation. We find that centrifugation in the presence of 3 M ammonium sulfate results in notable precipitation of DNA origami nanostructures but not of double-stranded genomic DNA. The precipitated DNA origami nanostructures can be resuspended in ammonium sulfate-free buffer without apparent formation of aggregates or loss of structural integrity. Even though quasi-1D six-helix bundle DNA origami are slightly less susceptible toward salting-out than more compact DNA origami triangles and 24-helix bundles, precipitation and recovery yields appear to be mostly independent of DNA origami shape and superstructure. Exploiting the specificity of ammonium sulfate salting-out for DNA origami nanostructures, we further apply this method to separate DNA origami triangles from genomic DNA fragments in a complex mixture. Our results thus demonstrate the possibility of concentrating and purifying DNA origami nanostructures by ammonium sulfate-induced salting-out.

Lactic Acid Bacteria Fermentation and Endopeptidase Treatment Improve the Functional and Nutritional Features of Arthrospira platensis

This study aimed at investigating the effect of fermentation and enzymatic treatment on the degree of proteolysis of wet (WB), dried at low temperature (DB), and freeze-dried Spirulina (LB) proteins that affect the nutritional (e.g., amino acid content and profiles, and protein digestibility) and functional (e.g., antioxidant and antimicrobial activities) properties. The desiccation treatments influenced the unprocessed Spirulina characteristics because, compared with that in WB, peptides and free amino acids content was 73% lower in DB and 34% higher in LB. An integrated approach, including chromatographic and electrophoresis analyses, was used to evaluate the effect of the different bioprocessing options on protein profiles, release of peptides and amino acids, and the overall protein digestibility. Compared with the application of fermentation with the selected Lactiplantibacillus plantarum T0A10, the treatment with the endopeptidase Alcalase^®, alone or combined, determined the most intense proteolysis. Moreover, the treatment with Alcalase^® of LB allowed the release of potentially bioactive compounds that are able to inhibit Penicillium roqueforti growth, whereas the combination of fermentation with L. plantarum T0A10 and Alcalase^® treatment increased Spirulina antioxidant properties, as determined by the scavenging activity toward ABTS radical (up to 60%) and antimicrobial activity against food pathogen Escherichia coli.

Fruit Derived Potentially Bioactive Bioengineered Silver Nanoparticles

INTRODUCTION

Protein-derived biogenic syntheses of inorganic nanoparticles have gained immense attention because of their broad spectrum of applications. Proteins offer a reducing environment to enable the synthesis of nanoparticles and encapsulate synthesized nanoparticles and provide them temporal stability in addition to biocompatibility.

METHODS

In the present study, Benincasa hispida fruit proteins were used to synthesize silver nanoparticles (AgNPs) at 37 °C over five days of incubation. The synthesis of AgNPs was confirmed by UV-Vis spectroscopy, TEM, zeta potential, and DLS analyses. Further, these NPs depicted antibacterial and antibiofilm effects. Additionally, the anticancer activities of nanoparticles were also tested against the lung cancer cell line (A549) with respect to the normal cell line (NRK) using MTT assay. Further, the estimation of ROS generation through DCFH-DA staining along with a reduction in mitochondrial membrane potential by Mito Tracker Red CMX staining was carried out. Moreover, nuclear degradation in the AgNPs treated cells was cross-checked by DAPI staining.

RESULTS

The average size of AgNPs was detected to be 27 ±1 nm by TEM analysis, whereas surface encapsulation by protein was determined by FTIR spectroscopy. These NPs were effective against bacterial pathogens such as Escherichia coli, Staphylococcus aureus, Salmonella enteric, and Staphylococcus epidermis with MICs of 148.12 µg/mL, 165.63 µg/mL, 162.77 µg/mL, and 124.88 µg/mL, respectively. Furthermore, these nanoparticles inhibit the formation of biofilms of E. coli, S. aureus, S. enteric, and S. epidermis by 71.14%, 73.89%, 66.66%, and 64.81%, respectively. Similarly, these nanoparticles were also found to inhibit (IC50 = 57.11 µM) the lung cancer cell line (A549). At the same time, they were non-toxic against NRK cells up to a concentration of 200 µM.

DISCUSSION

We successfully synthesized potentially potent antibacterial, antibiofilm and anticancer biogenic AgNPs.

Proteomic Analysis Demonstrates a Molecular Dialog Between Trichoderma guizhouense NJAU 4742 and Cucumber (Cucumis sativus L.) Roots: Role in Promoting Plant Growth

Trichoderma is a genus of filamentous fungi that play notable roles in stimulating plant growth after colonizing the root surface. However, the key proteins and molecular mechanisms governing this stimulation have not been completely elucidated. In this study, Trichoderma guizhouense NJAU 4742 was investigated in a hydroponic culture system after interacting with cucumber roots. The total proteins of the fungus were characterized, and the key metabolic pathways along with related genes were analyzed through proteomic and transcriptomic analyses. The roles played by the regulated proteins during the interaction between plants and NJAU 4742 were further examined. The intracellular or extracellular proteins from NJAU 4742 and extracellular proteins from cucumber were quantified, and the high-abundance proteins were determined which were primarily involved in the shikimate pathway (tryptophan, tyrosine, and phenylalanine metabolism, auxin biosynthesis, and secondary metabolite synthesis). Moreover, ¹⁵N-KNO₃ labeling analysis indicated that NJAU 4742 had a strong ability to convert nitrogenous amino acids, nitrate, nitrile, and amines into ammonia. The auxin synthesis and ammonification metabolism pathways of NJAU 4742 significantly contributed to plant growth. The results of this study demonstrated the crucial metabolic pathways involved in the interactions between Trichoderma spp. and plants.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

The Effect of Growth Stage and Isolation Method on Properties of ClearColi™ Outer Membrane Vesicles (OMVs)

Outer membrane vesicles (OMVs) are nanosized spherical blebs derived from the outer membrane of gram-negative bacteria. Outer membrane vesicles (OMVs) play important roles in various physiological functions of bacteria. They can be applied as native vaccines or vaccine adjuvants. The objective of this study was to determine the appropriate growth phase and isolation method for OMV separation from ClearColi™, an endotoxin-free strain of E. coli. It was demonstrated that the yield of OMVs is increased while the bacteria are growing. Herein, although total protein concentration of OMVs isolated from the stationary phase is more than other phases; the pre-stationary phase was selected for OMV isolation due to release of smaller size of OMVs as compared to other phases. In the current study, to obtain OMVs with high yield, proper size, and homogeneity, different concentration methods including protein precipitation by ammonium sulfate (AS) and ultrafiltration (UF) were combined to ultracentrifugation (UC) or precipitation-based exosome isolation kit. Among the examined isolation methods, AS (70%) + UC resulted in the highest yield of OMVs. The TEM results demonstrated bilayer round-shaped OMVs isolated by this method. Although AS (70%) + kit resulted in more heterogeneous in size and larger OMVs as compared to AS (70%) + UC, it is applicable when high yield of OMVs is required and UC is not available. Totally, isolation of ClearColi™ OMVs from pre-stationary phase using AS (70%) + UC with enhanced yield can be applied in vaccine research studies.

Surface functionalization-dependent localization and affinity of SiO2 nanoparticles within the biofilm EPS matrix

The contribution of the biofilm extracellular polymeric substance (EPS) matrix to reduced antimicrobial susceptibility in biofilms is widely recognised. As such, the direct targeting of the EPS matrix is a promising biofilm control strategy that allows for the disruption of the matrix, thereby allowing a subsequent increase in susceptibility to antimicrobial agents. To this end, surface-functionalized nanoparticles (NPs) have received considerable attention. However, the fundamental understanding of the interactions occurring between engineered NPs and the biofilm EPS matrix has not yet been fully elucidated. An insight into the underlying mechanisms involved when a NP interacts with the EPS matrix will aid in the design of more efficient NPs for biofilm control. Here we demonstrate the use of highly specific fluorescent probes in confocal laser scanning microscopy (CLSM) to illustrate the distribution of EPS macromolecules within the biofilm. Thereafter, a three-dimensional (3D) colocalization analysis was used to assess the affinity of differently functionalized silica NPs (SiNPs) and EPS macromolecules from Pseudomonas fluorescens biofilms. Results show that both the charge and surface functional groups of SiNPs dramatically affected the extent to which SiNPs interacted and localized with EPS macromolecules, including proteins, polysaccharides and DNA. Hypotheses are also presented about the possible physicochemical interactions which may be dominant in EPS matrix-NP interactions. This research not only develops an innovative CLSM-based methodology for elucidating biofilm-nanoparticle interactions but also provides a platform on which to build more efficient NP systems for biofilm control.

A review on recovery of proteins from industrial wastewaters with special emphasis on PHA production process: Sustainable circular bioeconomy process development

The economy of the polyhydroxyalkanoate (PHA) production process could be supported by utilising the different by-products released simultaneously during its production. Among these, proteins are present in high concentrations in liquid stream which are released after the cell disruption along with PHA granules. These microbial proteins can be used as animal feed, adhesive material and in manufacturing of bioplastics. The recycling of the protein containing liquid stream also serves as a promising approach to maintain circular bioeconomy in the route. For this aim, it is important to obtain good yield and limit the drawbacks of protein recovery processes and associated costs. The review focuses on recycling of the liquid stream generated during acid/thermal-alkali treatment for PHA production that would close the gap in linear economy and attain circularity in the process. Examples to recover proteins from other industrial waste streams along with their applications have also been discussed.

Purification of Antibodies From Human Milk and Infant Digestates for Viral Inhibition Assays

Oral administration of enteric pathogen-specific immunoglobulins may be an ideal approach for preventing infectious diarrhea in infants and children. For oral administration to be effective, antibodies must survive functionally intact within the highly proteolytic digestive tract. As an initial step toward assessing the viability of this approach, we examined the survival of palivizumab, a recombinant monoclonal antibody (IgG1κ), across infant digestion and its ability to neutralize respiratory syncytial virus (RSV). Human milk and infant digestive samples contain substances known to interfere with the RSV neutralization assay (our selected functional test for antibody survival through digestion), therefore, antibody extraction from the matrix was required prior to performing the assay. The efficacy of various approaches for palivizumab purification from human milk, infant's gastric and intestinal digestates, including casein precipitation, salting out, molecular weight cut-off, and affinity chromatography (protein A and G) were compared. Affinity chromatography using protein G with high-salt elution followed by 30-kDa molecular weight cut-off centrifugal filtration was the most effective technique for purifying palivizumab from human milk and infant digestates with a high yield and reduced background interference for the viral neutralization assay. This work is broadly applicable to the optimal isolation of antibodies from human milk and infant digesta for viral neutralization assays, enables the examination of how digestion affects the viral neutralization capacity of antibodies within milk and digestive samples, and paves the way for assessment of the viability of oral administration of recombinant antibodies as a therapeutic approach to prevent enteric pathogen-induced infectious diarrhea in infants.

From Silk Spinning to 3D Printing: Polymer Manufacturing using Directed Hierarchical Molecular Assembly

Silk spinning offers an evolution-based manufacturing strategy for industrial polymer manufacturing, yet remains largely inaccessible as the manufacturing mechanisms in biological and synthetic systems, especially at the molecular level, are fundamentally different. The appealing characteristics of silk spinning include the sustainable sourcing of the protein material, the all-aqueous processing into fibers, and the unique material properties of silks in various formats. Substantial progress has been made to mimic silk spinning in artificial manufacturing processes, despite the gap between natural and artificial systems. This report emphasizes the universal spinning conditions utilized by both spiders and silkworms to generate silk fibers in nature, as a scientific and technical framework for directing molecular assembly into high-performance structures. The preparation of regenerated silk feedstocks and mimicking native spinning conditions in artificial manufacturing are discussed, as is progress and challenges in fiber spinning and 3D printing of silk-composites. Silk spinning is a biomimetic model for advanced and sustainable artificial polymer manufacturing, offering benefits in biomedical applications for tissue scaffolds and implantable devices.

Time-temperature-resolved functional and structural changes of phycocyanin extracted from Arthrospira platensis/Spirulina

Arthrospira platensis, commonly known as Spirulina, gains increasing importance as alternative protein source for food production and biotechnological systems. A promising area is functional high-value algae extracts, rich in phycocyanin, a protein-pigment complex derived from A. platensis. This complex has proven functionality as the only natural blue colorant, fluorescent marker and therapeutic agent. The structure-function relationship is heat sensitive, making thermal processing in its production and its subsequent application a crucial aspect. In continuous high-temperature short-time treatments, it was shown how a purified phycocyanin (mixture of allophycocyanin and c-phycocyanin) disassembled and denatured between 50 and 70 °C. Three characteristic transition temperatures were allocated to specific quaternary aggregates. In contrast to sequential chemical denaturation, phycocyanin's chromophore and protein structure were simultaneously affected by thermal processing. Through a functionality assessment, the findings help optimize the efficiency of raw material usage by defining a processing window, enabling targeted process control resulting in desired product properties.

Hyperstabilization of a thermophile bacterial laccase and its application for industrial dyes degradation

In the present study, a novel extracellular laccase isolated from Geobacillus stearothermophilus ATCC 10149 was entrapped in a bionanocomposite matrix consisting of copper alginate (Cu-alginate) supplemented with the nanoclay bentonite. After optimization, this nanobiocatalyst was able to degrade up to 90% of Remazol Brilliant Blue R (RBBR) without the addition of redox mediators and retained 70% of its initial activity for at least 1440 h, equivalent to more than 288 uses. The incorporation of nanoclay allowed alginate beads to be used in alkaline pH and strengthened its mechanical properties. Besides, this thermophilic laccase was able to decolorize other structurally different synthetic dyes such as Methyl Orange, Malachite Green and Indigo Carmine. These preliminary results suggested that the nanobiocatalyst could be a suitable option for dye decolorization and be further developed for large scale bioremediation of toxic dyes.

Suitability of individual and bulk milk samples to investigate the humoral immune response to lumpy skin disease vaccination by ELISA

Background

The detection of antibodies against capripoxvirus has become easier with a commercially available ELISA validated for serum and plasma. In order to explore its suitability for immunological investigations on alternative samples, this study targeted milk as sample matrix available through non-invasive sampling.

Methods

Samples for this study were collected from dairy cows vaccinated against LSD in an area without reported LSD virus circulation. Paired serum and milk (individual and bulk) samples were tested by ELISA without and with modifications of the sample incubation time for the milk samples. For the evaluation of the test specificity, 352 milk samples from a milk repository in Germany were used as negative control. Receiver operating characteristic analysis was performed for determination of the Youden index and determination of the most suitable cut-off value for maximum specificity.

Results

From 154 analyzed serum samples from Serbia, 75 were detected as positive in the ELISA. Sensitivity and specificity of the ELISA test for milk samples reached values of 88 to 91% using Youden criteria. A cut-off of 10 was determined aiming for maximum specificity. This cut-off value was used for further analysis. Using the protocol for serum, out of 154 milk samples, 38 were detected as positive, number of positive detected milk samples increase up to 48 with modified protocol. Milk samples from Germany reacted negative, except two samples that had borderline results using modified protocol. Significant statistical difference (p < 0.05) was observed between two incubation protocols. The detection of LSD-specific antibodies from bulk milk samples (pools of 2–10 individuals) came along with a reduced sensitivity over the sample of individual animals.

Conclusions

Results show that the detection of capripoxvirus specific antibodies in milk samples using the commercially available ELISA from IDvet is feasible and can represent a helpful tool for LSDV monitoring programs.

Application of a Liquid Biphasic Flotation (LBF) System for Protein Extraction from Persiscaria Tenulla Leaf

Persiscaria tenulla, commonly known as Polygonum, is a plant belonging to the family Polygonaceae, which originated from and is widely found in Southeast Asia countries, such as Indonesia, Malaysia, Thailand, and Vietnam. The leaf of the plant is believed to have active ingredients that are responsible for therapeutic effects. In order to take full advantage of a natural medicinal plant for the application in the pharmaceutical and food industries, extraction and separation techniques are essential. In this study, an emerging and rapid extraction approach known as liquid biphasic flotation (LBF) is proposed for the extraction of protein from Persiscaria tenulla leaves. The scope of this study is to establish an efficient, environmentally friendly, and cost-effective technology for the extraction of protein from therapeutic leaves. Based on the ideal conditions of the small LBF system, a 98.36% protein recovery yield and a 79.12% separation efficiency were achieved. The upscaling study of this system exhibited the reliability of this technology for large-scale applications with a protein recovery yield of 99.44% and a separation efficiency of 93.28%. This technology demonstrated a simple approach with an effective protein recovery yield and separation that can be applied for the extraction of bioactive compounds from various medicinal-value plants.

Progress toward sourcing plants for new bioconjugation tools: a screening evaluation of a model peptide ligase using a synthetic precursor

In the present study, leaves from 39 phylogenetically distant plant species were sampled and screened for asparaginyl endopeptidase ligase activity using mass spectrometry to test the generality of peptide ligases in plants. A modified version of the sunflower trypsin inhibitor-1 precursor was used as the substrate for reactions with leaf crude extracts and protein fractions. Masses consistent with products of asparaginyl endopeptidase activities that cleave and ligate the substrate into cyclic peptide following the reactions were detected in 8 plants: Nerium oleander and Thevetia peruviana of the family Apocynaceae; Bauhinia variegata, Dermatophyllum secundiflorum, Pithecellobium flexicaule, and Prosopis chilensis of the family Fabaceae; Morus alba of the family Moraceae; and Citrus aurantium of the family Rutaceae. This screening result represents a 20% hit rate for finding asparaginyl endopeptidase ligase activity from the arbitrary plants sampled. Analysis following a 2-h reaction of the substrate with the crude extract of D. secundiflorum leaves showed that the yield of cyclic peptide remained stable around 0.5 ± 0.1% of the substrate over the course of the reaction.

Effect of Bacillus tequilensis SALBT crude extract with pectinase activity on demucilation of coffee beans and juice clarification

Pectinases are a group of enzymes, which catalyze the breakdown of pectin with numerous applications in various industries. Microbes are the predominant pectinase producers. In the present study, bacterial species were isolated from the soil of a vegetable and fruit dump yard area in a market. The species screened and isolated were identified as Bacillus tequilensis SALBT, and the media and culture conditions were optimized for enhanced production of total pectinases. Maximum pectinolytic activity was observed with 1.5% (w/v) pectin concentration with a combination of yeast extract as nitrogen source and MgSO₄ as a metal ion source. Carbon/nitrogen in 2:1 ratio (w/v) yielded the maximum pectinase production with pH and temperature of the medium of 7.5°C and 40°C, respectively. Pectinase activity was determined by the dinitrosalicylic acid method. The pectinase production was relatively stable in the presence of various surfactants like Tween (20, 40, 60, and 80) and sodium dodecyl sulfate (SDS), whereas Triton X-100 showed an inhibitory effect. Mass production of the enzyme in optimized media and partial purification was performed by ammonium sulfate precipitation followed by dialysis. The approximate molecular weight of the partially purified pectinase was found to be 35 kDa by SDS-polyacrylamide gel electrophoresis. Application studies such as demucilaging coffee beans and juice clarification were also performed. The findings revealed that B. tequilensis SALBT with pectinase activity has the ability to remove the mucilage layer of pulped coffee seeds, and the partially purified pectinases found to be effective in clarifying juice.

Production of Active Poly- and Oligosaccharidic Fractions from Ulva sp. by Combining Enzyme-Assisted Extraction (EAE) and Depolymerization

Data on fractionation and depolymerization of the matrix ulvan polysaccharides, and studies on the biological activities on skin cells, are very scarce. In this work, crude ulvans were produced by using EAE (enzyme-assisted extraction) and compared to maceration (an established procedure). After different fractionation procedures-ethanolic precipitation, dialysis, or ammonium sulfate precipitation-the biochemical composition showed that EAE led to an increased content in ulvans. Coupling EAE to sulfate ammonium precipitation led to protein enrichment. Oligosaccharides were obtained by using radical depolymerization by H2O2 and ion-exchange resin depolymerization. Sulfate groups were partially cleaved during these chemical treatments. The potential bioactivity of the fractions was assessed using a lipoxygenase inhibition assay for anti-inflammatory activity and a WST-1 assay for human dermal fibroblast viability and proliferation. All ulvans extracts, poly- and oligosaccharidic fractions from EAE, expanded the fibroblast proliferation rate up to 62%. Our research emphasizes the potential use of poly- and oligosaccharidic fractions of Ulva sp. for further development in cosmetic applications.

Cross-talk between physiological and biochemical adjustments by Punica granatum cv. Dente di cavallo mitigates the effects of salinity and ozone stress

Plants are exposed to a broad range of environmental stresses, such as salinity and ozone (O₃), and survive due to their ability to adjust their metabolism. The aim of this study was to evaluate the physiological and biochemical adjustments adopted by pomegranate (Punica granatum L. cv. Dente di cavallo) under realistic field conditions. One-year-old saplings were exposed to O₃ [two levels denoted as ambient (AO) and elevated (EO) O₃ concentrations] and salinity [S (salt, 50 mM NaCl)] for three consecutive months. No salt (NS) plants received distilled water. Despite the accumulation of Na⁺ and Cl^- in the aboveground biomass, no evidence of visible injury due to salt (e.g. tip yellow-brown lesions) was found. The maintenance of leaf water status (i.e. unchanged values of electrolytic leakage and relative water content), the significant increase of abscisic acid, proline and starch content (+98, +65 and +59% compared to AO_NS) and stomatal closure (-24%) are suggested to act as adaptive mechanisms against salt stress in AO_S plants. By contrast, EO_NS plants were unable to protect cells against the negative impact of O₃, as confirmed by the reduction of the CO₂ assimilation rate (-21%), accumulation of reactive oxygen species (+10 and +225% of superoxide anion and hydrogen peroxide) and malondialdehyde by-product (about 2-fold higher than AO_NS). Plants tried to preserve themselves from further oxidative damage by adopting some biochemical adjustments [i.e. increase in proline content (+41%) and induction of catalase activity (8-fold higher than in AO_NS)]. The interaction of the two stressors induced responses considerably different to those observed when each stressor was applied independently. An analysis of the antioxidant pool revealed that the biochemical adjustments adopted by P. granatum under EO_S conditions (e.g. reduction of total ascorbate; increased activities of superoxide dismutase and catalase) were not sufficient to ameliorate the O₃-induced oxidative stress.

Two purified proteins from royal jelly with in vitro dual anti-hepatic damage potency: Major royal jelly protein 2 and its novel isoform X1

Liver diseases are serious life-threating conditions that should be controlled. Here, we identify a protein fraction from royal-jelly (RJ) that represents the most effective composite against CCl₄-induced hepatotoxicity and HepG2 cell growth. Two closely related proteins were purified from this fraction by a new simple method and identified by MALDI-TOF MS as major RJ protein 2 (MRJP2) and its predicted isoform X1. The in silico assessment (3D structures and functions) of these proteins were performed using Iterative Threading ASSEmbly Refinement (I-TASSER) analysis and RAMPAGE program. These two purified proteins were able to relieve the necrotic hepatocytes (by 60.4%) via reducing tumor necrosis factor (TNF)-α, mixed lineage kinase domain-like protein (MLKL) and intracellular reactive species. The latter effects associated with improving hepatocyte functions. Furthermore, they revealed the potent anticancer effect via induction of caspase-dependent apoptosis and controlling the expression of both Bcl-2 and p53 in HepG2 cells. Thus, MRJP2 and its isoform X1 can be a promising dual strategy for fighting hepatic injury and cancer in future animal and human studies.

Repurposing Biocatalysts to Control Radical Polymerizations

Reversible-deactivation radical polymerizations (controlled radical polymerizations) have revolutionized and revitalized the field of polymer synthesis. While enzymes and other biologically derived catalysts have long been known to initiate free radical polymerizations, the ability of peroxidases, hemoglobin, laccases, enzyme-mimetics, chlorophylls, heme, red blood cells, bacteria, and other biocatalysts to control or initiate reversible-deactivation radical polymerizations has only been described recently. Here, the scope of biocatalytic atom transfer radical polymerizations (bioATRP), enzyme-initiated reversible addition-fragmentation chain transfer radical polymerizations (bioRAFT), biocatalytic organometallic-mediated radical polymerizations (bioOMRP), and biocatalytic reversible complexation mediated polymerizations (bioRCMP) is critically reviewed, and the potential of these reactions for the environmentally friendly synthesis of precision polymers, for the preparation of functional nanostructures, for the modification of surfaces, and for biosensing is discussed.

CfPDIP1, a novel secreted protein of Colletotrichum falcatum, elicits defense responses in sugarcane and triggers hypersensitive response in tobacco

Colletotrichum falcatum, a hemibiotrophic fungal pathogen, causes one of the major devastating diseases of sugarcane-red rot. C. falcatum secretes a plethora of molecular signatures that might play a crucial role during its interaction with sugarcane. Here, we report the purification and characterization of a novel secreted protein of C. falcatum that elicits defense responses in sugarcane and triggers hypersensitive response (HR) in tobacco. The novel protein purified from the culture filtrate of C. falcatum was identified by MALDI TOF/TOF MS and designated as C. falcatum plant defense-inducing protein 1 (CfPDIP1). Temporal transcriptional profiling showed that the level of CfPDIP1 expression was greater in incompatible interaction than the compatible interaction until 120 h post-inoculation (hpi). EffectorP, an in silico tool, has predicted CfPDIP1 as a potential effector. Functional characterization of full length and two other domain deletional variants (CfPDIP1ΔN1-21 and CfPDIP1ΔN1-45) of recombinant CfPDIP1 proteins has indicated that CfPDIP1ΔN1-21 variant elicited rapid alkalinization and induced a relatively higher production of hydrogen peroxide (H2O2) in sugarcane suspension culture. However, in Nicotiana tabacum, all the three forms of recombinant CfPDIP1 proteins triggered HR along with the induction of H2O2 production and callose deposition. Further characterization using detached leaf bioassay in sugarcane revealed that foliar priming with CfPDIP1∆1-21 has suppressed the extent of lesion development, even though the co-infiltration of CfPDIP1∆1-21 with C. falcatum on unprimed leaves increased the extent of lesion development than control. Besides, the foliar priming has induced systemic expression of major defense-related genes with the concomitant reduction of pathogen biomass and thereby suppression of red rot severity in sugarcane. Comprehensively, the results have suggested that the novel protein, CfPDIP1, has the potential to trigger a multitude of defense responses in sugarcane and tobacco upon priming and might play a potential role during plant-pathogen interactions.

Measuring myeloperoxidase activity in biological samples

BACKGROUND

Enzymatic activity measurements of the highly oxidative enzyme myeloperoxidase (MPO), which is implicated in many diseases, are widely used in the literature, but often suffer from nonspecificity and lack of uniformity. Thus, validation and standardization are needed to establish a robust method that is highly specific, sensitive, and reproducible for assaying MPO activity in biological samples.

PRINCIPAL FINDINGS

We found conflicting results between in vivo molecular MR imaging of MPO, which measures extracellular activity, and commonly used in vitro MPO activity assays. Thus, we established and validated a protocol to obtain extra- and intracellular MPO from murine organs. To validate the MPO activity assays, three different classes of MPO activity assays were used in spike and recovery experiments. However, these assay methods yielded inconsistent results, likely because of interfering substances and other peroxidases present in tissue extracts. To circumvent this, we first captured MPO with an antibody. The MPO activity of the resultant samples was assessed by ADHP and validated against samples from MPO-knockout mice in murine disease models of multiple sclerosis, steatohepatitis, and myocardial infarction. We found the measurements performed using this protocol to be highly specific and reproducible, and when performed using ADHP, to be highly sensitive over a broad range. In addition, we found that intracellular MPO activity correlated well with tissue neutrophil content, and can be used as a marker to assess neutrophil infiltration in the tissue.

CONCLUSION

We validated a highly specific and sensitive assay protocol that should be used as the standard method for all MPO activity assays in biological samples. We also established a method to obtain extra- and intracellular MPO from murine organs. Extracellular MPO activity gives an estimate of the oxidative stress in inflammatory diseases, while intracellular MPO activity correlates well with tissue neutrophil content. A detailed step-by-step protocol is provided.