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Journal of Materials Chemistry. B May 2024The formation of transient structures plays important roles in biological processes, capturing temporary states of matter through influx of energy or biological reaction...
The formation of transient structures plays important roles in biological processes, capturing temporary states of matter through influx of energy or biological reaction networks catalyzed by enzymes. These natural transient structures inspire efforts to mimic this elegant mechanism of structural control in synthetic analogues. Specifically, though traditional supramolecular materials are designed on the basis of equilibrium formation, recent efforts have explored out-of-equilibrium control of these materials using both direct and indirect mechanisms; the preponderance of such works has been in the area of low molecular weight gelators. Here, a transient supramolecular hydrogel is realized through cucurbit[7]uril host-guest physical crosslinking under indirect control from a biocatalyzed network that regulates and oscillates pH. The duration of transient hydrogel formation, and resulting mechanical properties, are tunable according to the dose of enzyme, substrate, or pH stimulus. This tunability enables control over emergent functions, such as the programmable burst release of encapsulated model macromolecular payloads.
Topics: Hydrogels; Hydrogen-Ion Concentration; Imidazoles; Bridged-Ring Compounds; Macromolecular Substances; Biocatalysis; Molecular Structure; Muramidase
PubMed: 38647183
DOI: 10.1039/d4tb00545g -
IUCrJ May 2024Metal-based complexes with their unique chemical properties, including multiple oxidation states, radio-nuclear capabilities and various coordination geometries yield...
Metal-based complexes with their unique chemical properties, including multiple oxidation states, radio-nuclear capabilities and various coordination geometries yield value as potential pharmaceuticals. Understanding the interactions between metals and biological systems will prove key for site-specific coordination of new metal-based lead compounds. This study merges the concepts of target coordination with fragment-based drug methodologies, supported by varying the anomalous scattering of rhenium along with infrared spectroscopy, and has identified rhenium metal sites bound covalently with two amino acid types within the model protein. A time-based series of lysozyme-rhenium-imidazole (HEWL-Re-Imi) crystals was analysed systematically over a span of 38 weeks. The main rhenium covalent coordination is observed at His15, Asp101 and Asp119. Weak (i.e. noncovalent) interactions are observed at other aspartic, asparagine, proline, tyrosine and tryptophan side chains. Detailed bond distance comparisons, including precision estimates, are reported, utilizing the diffraction precision index supplemented with small-molecule data from the Cambridge Structural Database. Key findings include changes in the protein structure induced at the rhenium metal binding site, not observed in similar metal-free structures. The binding sites are typically found along the solvent-channel-accessible protein surface. The three primary covalent metal binding sites are consistent throughout the time series, whereas binding to neighbouring amino acid residues changes through the time series. Co-crystallization was used, consistently yielding crystals four days after setup. After crystal formation, soaking of the compound into the crystal over 38 weeks is continued and explains these structural adjustments. It is the covalent bond stability at the three sites, their proximity to the solvent channel and the movement of residues to accommodate the metal that are important, and may prove useful for future radiopharmaceutical development including target modification.
Topics: Rhenium; Muramidase; Organometallic Compounds; Drug Development; Crystallography, X-Ray; Binding Sites; Coordination Complexes; Imidazoles; Models, Molecular
PubMed: 38639558
DOI: 10.1107/S2052252524002598 -
International Journal of Molecular... Apr 2024This study aimed to elucidate the similarities and differences between amyloid-forming corpora amylacea (CA) in the prostate and lung, examine the nature of CAs in... (Review)
Review
This study aimed to elucidate the similarities and differences between amyloid-forming corpora amylacea (CA) in the prostate and lung, examine the nature of CAs in cystic tumors of the atrioventricular node (CTAVN), and clarify the distinctions between amyloid-forming CA and spheroid-type amyloid deposition. We conducted proteomics analyses using liquid chromatography-tandem mass spectrometry with laser microdissection and immunohistochemistry to validate the characteristics of CAs in the lung and prostate. Our findings revealed that the CAs in these organs primarily consisted of common proteins (β2-microglobulin and lysozyme) and locally produced proteins. Moreover, we observed a discrepancy between the histopathological and proteomic analysis results in CTAVN-associated CAs. In addition, while the histopathological appearance of the amyloid-forming CAs and spheroid-type amyloid deposits were nearly identical, the latter deposition lacked β2-microglobulin and lysozyme and exhibited evident destruction of the surrounding tissue. A literature review further supported these findings. These results suggest that amyloid-forming CAs in the lung and prostate are formed through a shared mechanism, serving as waste containers (wasteosomes) and/or storage for excess proteins (functional amyloids). In contrast, we hypothesize that while amyloid-forming CA and spheroid-type amyloid deposits are formed, in part, through common mechanisms, the latter are pathological.
Topics: Male; Humans; Muramidase; Immunohistochemistry; Plaque, Amyloid; Proteomics; Amyloidogenic Proteins
PubMed: 38612850
DOI: 10.3390/ijms25074040 -
Journal of Animal Science and... Apr 2024Optimal gut health is important to maximize growth performance and feed efficiency in broiler chickens. A total of 1,365 one-day-old male Ross 308 broiler chickens were...
BACKGROUND
Optimal gut health is important to maximize growth performance and feed efficiency in broiler chickens. A total of 1,365 one-day-old male Ross 308 broiler chickens were randomly divided into 5 treatments groups with 21 replicates, 13 birds per replicate. The present research investigated effects of microbial muramidase or a precision glycan alone or in combination on growth performance, apparent total tract digestibility, total blood carotenoid content, intestinal villus length, meat quality and gut microbiota in broiler chickens. Treatments included: NC: negative control (basal diet group); PC: positive control (basal diet + 0.02% probiotics); MR: basal diet + 0.035% microbial muramidase; PG: basal diet + 0.1% precision glycan; and MRPG: basal diet + 0.025% MR + 0.1% PG, respectively.
RESULTS
MRPG group increased the body weight gain and feed intake (P < 0.05) compared with NC group. Moreover, it significantly increased total serum carotenoid (P < 0.05) and MRPG altered the microbial diversity in ileum contents. The MRPG treatment group increased the abundance of the phylum Firmicutes, and family Lachnospiraceae, Ruminococcaceae, Oscillospiraceae, Lactobacillaceae, Peptostreptococcaceae and decreased the abundance of the phylum Campilobacterota, Bacteroidota and family Bacteroidaceae. Compared with the NC group, the chickens fed MRPG showed significantly increased in duodenum villus length at end the trial.
CONCLUSION
In this study, overall results showed that the synergetic effects of MR and PG showed enhancing growth performance, total serum carotenoid level and altering gut microbiota composition of broilers. The current research indicates that co-supplementation of MR and PG in broiler diets enhances intestinal health, consequently leading to an increased broiler production.
PubMed: 38594781
DOI: 10.1186/s40104-024-01010-x -
Chemical & Pharmaceutical Bulletin 2024Polymeric nanofibers generated via electrospinning offer a promising platform for drug delivery systems. This study examines the application of electrospun polyvinyl...
Polymeric nanofibers generated via electrospinning offer a promising platform for drug delivery systems. This study examines the application of electrospun polyvinyl alcohol (PVA) nanofibers for controlled lysozyme (LZM) delivery. By using various PVA grades, such as the degree of polymerization/hydrolysis, this study investigates their influence on nanofiber morphology and drug-release characteristics. LZM-loaded PVA monolithic nanofibers having 50% drug content exhibit efficient entrapment, wherein rapid dissolution is achieved within 30 min. The initial burst of LZM from the nanofiber was reduced as the LZM content was lowered. The initial dissolution is greatly influenced by the choice of PVA grade used; fully hydrolyzed PVA nanofibers demonstrate controlled release due to the reduced water solubility of PVA. Furthermore, coaxial electrospinning, which creates core-shell nanofibers with polycaprolactone as a controlled release layer, enables sustained LZM release over an extended period. This study confirms a correlation between PVA characteristics and controlled drug release and provides valuable insights into tailoring nanofiber properties for pharmaceutical applications.
Topics: Polyvinyl Alcohol; Delayed-Action Preparations; Nanofibers; Muramidase; Drug Delivery Systems
PubMed: 38508743
DOI: 10.1248/cpb.c24-00024 -
Scientific Reports Mar 2024The study aimed to analyze the qualitative features of Cherry Valley duck' hatching eggs during storage at different temperatures. Eggs were divided into 3 equal groups...
The study aimed to analyze the qualitative features of Cherry Valley duck' hatching eggs during storage at different temperatures. Eggs were divided into 3 equal groups with 30 eggs each: fresh egg and stored at 7 °C and 17 °C within one week. Qualitative analyses of duck eggs were carried out, considering the morphological composition, physicochemical characteristics, lysozyme activity, and albumen viscosity. The highest weight of yolk and its percentage was found in the 17 °C group. The weight and percentage of albumen were significantly the highest in the group of fresh eggs. Higher egg weight loss was observed in the group stored at higher temperatures. Higher thick albumen height and Haugh units were found in fresh eggs and eggs stored at 7 °C. Different temperatures of egg storage did not affect lysozyme activity in thick and thin albumen. Stored eggs were characterized by lower albumen viscosity only at a shear rate of 10 rpm. The higher viscosity of thick albumen compared to thin ones was demonstrated at 10 and 20 rpm shear rates. The presented research results indicate a large diversity of selected qualitative indicators of hatching duck eggs, which may affect their storage and suitability for incubation.
Topics: Animals; Ducks; Muramidase; Temperature; Viscosity; Time Factors; Eggs; Albumins; Chickens
PubMed: 38454129
DOI: 10.1038/s41598-024-56351-4 -
Microbiology Spectrum Apr 2024The use of immune compounds as antimicrobial adjuvants is a classic idea recovering timeliness in the current antibiotic resistance scenario. However, the activity of...
UNLABELLED
The use of immune compounds as antimicrobial adjuvants is a classic idea recovering timeliness in the current antibiotic resistance scenario. However, the activity of certain antimicrobial peptides against ESKAPE Gram-negatives has not been sufficiently investigated. The objective of this study was to determine the activities of human defensins HNP-1 and hBD-3 alone or combined with permeabilizing/peptidoglycan-targeting agents against clinical ESKAPE Gram-negatives [ (AB), (EC), (KP), and acute/chronic (PA)]. Lethal concentrations (LCs) of HNP-1 and hBD-3 were determined in four collections of multidrug resistant EC, AB, KP, and PA clinical strains (10-36 isolates depending on the collection). These defensins act through membrane permeabilization plus peptidoglycan building blockade, enabling that alterations in peptidoglycan recycling may increase their activity, which is why different recycling-defective mutants were also included. Combinations with physiological lysozyme and subinhibitory colistin for bactericidal activities determination, and with meropenem for minimum inhibitory concentrations (MICs), were also assessed. HNP-1 showed undetectable activity (LC > 32 mg/L for all strains). hBD-3 showed appreciable activities: LC ranges 2-16, 8-8, 8->32, and 8->32 mg/L for AB, EC, KP, and PA, being PA strains from cystic fibrosis significantly more resistant than acute origin ones. None of the peptidoglycan recycling-defective mutants showed greater susceptibility to HNP-1/hBD-3. Combination with colistin or lysozyme did not change their bactericidal power, and virtually neither did meropenem + hBD-3 compared to meropenem MICs. This is the first study comparatively analyzing the HNP-1/hBD-3 activities against the ESKAPE Gram-negatives, and demonstrates interesting bactericidal capacities of hBD-3 mostly against AB and EC.
IMPORTANCE
In the current scenario of critical need for new antimicrobials against multidrug-resistant bacteria, all options must be considered, including classic ideas such as the use of purified immune compounds. However, information regarding the activity of certain human defensins against ESKAPE Gram-negatives was incomplete. This is the first study comparatively assessing the in vitro activity of two membrane-permeabilizing/peptidoglycan construction-blocking defensins (HNP-1 and hBD-3) against relevant clinical collections of ESKAPE Gram-negatives, alone or in combination with permeabilizers, additional peptidoglycan-targeting attacks, or the blockade of its recycling. Our data suggest that hBD-3 has a notable bactericidal activity against multidrug-resistant and strains that should be considered as potential adjuvant option. Our results suggest for the first time an increased resistance of strains from chronic infection compared to acute origin ones, and provide new clues about the predominant mode of action of hBD-3 against Gram-negatives (permeabilization rather than peptidoglycan-targeting).
Topics: Humans; Colistin; Muramidase; Peptidoglycan; Meropenem; Anti-Bacterial Agents; Anti-Infective Agents; Pseudomonas Infections; Microbial Sensitivity Tests; Drug Resistance, Multiple, Bacterial; alpha-Defensins
PubMed: 38441982
DOI: 10.1128/spectrum.00358-24 -
Yakugaku Zasshi : Journal of the... 2024This study focuses on the modulation of protein aggregation and immunogenicity. As a starting point for investigating long-range interactions within a non-native...
This study focuses on the modulation of protein aggregation and immunogenicity. As a starting point for investigating long-range interactions within a non-native protein, the effects of perturbing denatured protein states on their aggregation, including the formation of amyloid fibrils, were evaluated. The effects of adducts, sugar modifications, and stabilization on protein aggregation were then examined. We also investigated how protein immunogenicity was affected by enhancing protein conformational stability and other factors.
Topics: Muramidase; Protein Aggregates; Protein Conformation
PubMed: 38432940
DOI: 10.1248/yakushi.23-00192 -
Advanced Science (Weinheim,... May 2024Universal protein coatings have recently gained wide interest in medical applications due to their biocompatibility and ease of fabrication. However, the challenge...
Universal protein coatings have recently gained wide interest in medical applications due to their biocompatibility and ease of fabrication. However, the challenge persists in protein activity preservation, significantly complicating the functional design of these coatings. Herein, an active dual-protein surface engineering strategy assisted by a facile stepwise protein-protein interactions assembly (SPPIA) method for catheters to reduce clot formation and infection is proposed. This strategy is realized first by the partial oxidation of bovine serum albumin (BSA) and lysozyme (LZM) for creating stable nucleation platforms via hydrophobic interaction, followed by the assembly of nonoxidized BSA (pI, the isoelectric point, ≈4.7) and LZM (pI ≈11) through electrostatic interaction owing to their opposite charge under neutral conditions. The SPPIA method effectively preserves the conformation and functionality of both BSA and LZM, thus endowing the resultant coating with potent antithrombotic and bactericidal properties. Furthermore, the stable nucleation platform ensures the adhesion and durability of the coating, resisting thrombosis and bacterial proliferation even after 15 days of PBS immersion. Overall, the SPPIA approach not only provides a new strategy for the fabrication of active protein coatings but also shows promise for the surface engineering technology of catheters.
Topics: Serum Albumin, Bovine; Thrombosis; Animals; Coated Materials, Biocompatible; Muramidase; Surface Properties; Humans; Hydrophobic and Hydrophilic Interactions
PubMed: 38424734
DOI: 10.1002/advs.202310259 -
International Journal of Pharmaceutics Apr 2024This study aims to develop a new method to dry proteins based on protein-hyaluronic acid (HA) precipitation and apply the precipitation-redissolution technique to...
This study aims to develop a new method to dry proteins based on protein-hyaluronic acid (HA) precipitation and apply the precipitation-redissolution technique to develop highly concentrated protein formulations. Lysozyme was used as a model protein and HA with various molecular weights (MW) were investigated. Under low ionic strength, low-MW HA (e.g., MW: around 5 K) did not induce lysozyme precipitation. Conversely, high-MW HA (e.g., MW: approximately from 40 K to 1.5 M) precipitated more than 90 % of lysozyme. The dried lysozyme-HA precipitates had moisture levels between 4 % and 5 %. The lysozyme-HA precipitates could be redissolved using PBS (pH 7.4, ionic strength: ∼ 163 mM). The viscosity of the reconstituted solution was dependent on HA MW, e.g., 4 cP for HA40K, and 155 cP for HA1.5 M, suggesting low-MW HA might be a proper excipient for highly concentrated solution formulations for subcutaneous/intraocular injection and high-MW HA may fit for other applications. The tertiary structure of lysozyme after the precipitation-redissolution steps had no significant difference from that of the original lysozyme as confirmed by fluorescence spectroscopy. The denaturation temperature of lysozyme after the precipitation-redissolution steps and that of the original lysozyme were close, indicating they possessed similar thermal stability. The accelerated stability study revealed that lysozyme stored in the dry precipitates was more physically stable than that in the buffer solution. Overall, this new drying technique is suitable for drying proteins and exhibits several benefits such as minimum energy consumption, cost effectiveness, high production yield, and mild processing conditions. In addition, the precipitation-redissolution technique proposed in this study can potentially be used to develop highly concentrated formulations, especially for proteins experiencing poor stability in the liquid state.
Topics: Hyaluronic Acid; Muramidase; Proteins; Desiccation; Drug Compounding
PubMed: 38408551
DOI: 10.1016/j.ijpharm.2024.123940