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The Journal of Physical Chemistry... Jun 2024The effects of two macromolecular cosolutes, specifically the polysaccharide dextran-20 and the protein lysozyme, on the aggregation kinetics of a pathogenic huntingtin...
The effects of two macromolecular cosolutes, specifically the polysaccharide dextran-20 and the protein lysozyme, on the aggregation kinetics of a pathogenic huntingtin exon-1 protein (hht) with a 35 polyglutamine repeat, httQ, are described. A unified kinetic model that establishes a direct connection between reversible tetramerization occurring on the microsecond time scale and irreversible fibril formation on a time scale of hours/days forms the basis for quantitative analysis of httQ aggregation, monitored by measuring cross-peak intensities in a series of 2D H-N NMR correlation spectra acquired during the course of aggregation. The primary effects of the two cosolutes are associated with shifts in the prenucleation tetramerization equilibrium resulting in substantial changes in concentration of "preformed" httQ tetramers. Similar effects of the two cosolutes on the tetramerization equilibrium observed for a shorter, nonaggregating huntingtin variant with a 7-glutamine repeat, httQ, lend confidence to the conclusions drawn from the fits to the httQ aggregation kinetics.
Topics: Huntingtin Protein; Kinetics; Muramidase; Humans; Dextrans; Peptides; Nuclear Magnetic Resonance, Biomolecular; Protein Aggregates; Macromolecular Substances; Protein Multimerization; Magnetic Resonance Spectroscopy
PubMed: 38857530
DOI: 10.1021/acs.jpclett.4c01410 -
Journal of Biotechnology Aug 2024Lysozyme, an antimicrobial agent, is extensively employed in the food and healthcare sectors to facilitate the breakdown of peptidoglycan. However, the methods to...
Lysozyme, an antimicrobial agent, is extensively employed in the food and healthcare sectors to facilitate the breakdown of peptidoglycan. However, the methods to improve its catalytic activity and secretory expression still need to be studied. In the present study, twelve lysozymes from different origins were heterologously expressed using the Komagataella phaffii expression system. Among them, the lysozyme from the European flat oyster Ostrea edulis (oeLYZ) showed the highest activity. Via a semi-rational approach to reduce the structural free energy, the double mutant Y15A/S39R (oeLYZ) with the catalytic activity 1.8-fold greater than that of the wild type was generated. Subsequently, different N-terminal fusion tags were employed to enhance oeLYZ expression. The fusion with peptide tag 6×Glu resulted in a remarkable increase in the recombinant oeLYZdm expression, from 2.81 × 10 U mL to 2.11 × 10 U mL in shake flask culture, and eventually reaching 2.05 × 10 U mL in a 3-L fermenter. The work produced the greatest amount of heterologous oeLYZ expression in microbial systems that are known to exist. Reducing the structural free energy and employing the N-terminal fusion tags are effective strategies to improve the catalytic activity and secretory expression of lysozyme.
Topics: Muramidase; Animals; Ostrea; Recombinant Proteins
PubMed: 38848819
DOI: 10.1016/j.jbiotec.2024.05.011 -
International Journal of Biological... Jun 2024The development of high-efficiency molecularly imprinted photocatalysts is still challenging due to the lack of hydrophilic and suitable functional monomers. In this...
The development of high-efficiency molecularly imprinted photocatalysts is still challenging due to the lack of hydrophilic and suitable functional monomers. In this work, the bio-sourced lysozyme was developed as the hydrophilic functional monomer, and Cu-doped BiOBr was used as the photocatalysts, to prepare a novel hydrophilic molecularly imprinted lysozyme-BiOBr composite (BiOBr-Cu/LyzMIP) with enhanced visible light utilization. Lysozyme could form a transparent layer to mitigate the light transmission obstruction caused by the surface imprinting layer, making it an ideal functional monomer. The prepared BiOBr-Cu/LyzMIP possessed red-shifted visible-light absorption edge and minor reduction of light absorbance, indicating the enhanced utilization of visible light. Accordingly, BiOBr-Cu/LyzMIP demonstrated excellent degradation rate (99.4 % in 20 min), exceptional degradation efficiency (0.211 min), and superior reusability. Moreover, BiOBr-Cu/LyzMIP exhibited rapid adsorption equilibrium (20 min), good imprinting factor (2.67), and favourable degradation selectivity (>1.75), indicating the good imprinting effect resulting from abundant functional groups of lysozyme. Versatility experiments on different templates suggested that the proposed approach allowed flexibility in selecting a wide range of hazardous contaminants according to practical requirements. The present work expands the application of lysozyme-based composites in the environmental field, and provides a new one-stop pathway for efficient and sustainable treatment of contaminated water.
Topics: Muramidase; Water Pollutants, Chemical; Hydrophobic and Hydrophilic Interactions; Light; Molecular Imprinting; Water Purification; Adsorption; Copper; Catalysis
PubMed: 38844276
DOI: 10.1016/j.ijbiomac.2024.132910 -
Journal of Mass Spectrometry : JMS Jul 2024Analysis of noncovalent interactions between natural products and proteins is important for rapid screening of active ingredients and understanding their pharmacological...
Analysis of noncovalent interactions between natural products and proteins is important for rapid screening of active ingredients and understanding their pharmacological activities. In this work, the intensity fading MALDI-TOF mass spectrometry (IF-MALDI-MS) method with improved reproducibility was implemented to investigate the binding interactions between saponins from Panax notoginseng and lysozyme. The benchmark IF-MALDI-MS experiment was established using N,N',N″-triacetylchitotriose-lysozyme as a model system. The reproducibility of ion intensities in IF-MALDI-MS was improved by scanning the whole sample deposition with a focused laser beam. The relative standard deviation (RSD) of deposition scanning IF-MALDI-MS is 5.7%. Similar decay trends of the relative intensities of notoginseng saponins against increasing amounts of lysozyme were observed for all six notoginseng saponins. The half-maximal fading concentration (FC) was calculated to quantitatively characterize the binding affinity of each ligand based on the decay curve. According to the FC values obtained, the binding affinities of the six notoginseng saponins were evaluated in the following order: notoginsenoside S > notoginsenoside Fc > ginsenoside Rb1 > ginsenoside Rd > notoginsenoside Ft1 > ginsenoside Rg1. The binding order was in accordance with molecular docking studies, which showed hydrogen bonding might play a key role in stabilizing the binding interaction. Our results demonstrated that deposition scanning IF-MALDI-MS can provide valuable information on the noncovalent interactions between ligands and proteins.
Topics: Muramidase; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Saponins; Panax notoginseng; Protein Binding; Molecular Docking Simulation; Reproducibility of Results; Animals; Trisaccharides
PubMed: 38842112
DOI: 10.1002/jms.5058 -
Journal of Separation Science Jun 2024Chromatography is a technique of separation based on adsorption and/or interaction of target molecules with stationary phases. Herein, we report the design and...
Preparation of carboxyl-functionalized silica core-shell microspheres and their applications in weak cation exchange chromatography, heavy metal removal, and lysozyme enrichment.
Chromatography is a technique of separation based on adsorption and/or interaction of target molecules with stationary phases. Herein, we report the design and fabrication of BTDA@SiO core-shell microspheres as a new class of stationary phase and demonstrate its impressive performance for chromatographic separations. The silica microspheres of BTDA@SiO were synthesized by in situ method with 1,3,5-benzenetricarboxaldehyde and 3,5-diaminobenzoic to separate peptides and proteins on high-performance liquid chromatography. The BTDA@SiO core-shell structure has a high specific surface area and retention factor of 4.27 and 8.31 for anionic and cationic peptides, respectively. The separation factor and resolution were high as well. A typical chromatogram illustrated nearly baseline resolution of the two peptides in less than 3 min. The BTDA@SiO was also highly stable in the pH range of 1 to 14. Furthermore, the prepared BTDA@SiO core-shell material not only be used for chromatographic separation but also as heavy metal removal from water. Using a BTDA@SiO, we also achieved a lysozyme enrichment with a maximum saturated adsorption capacity reaching 714 mg/g. In summary, BTDA@SiO has great application prospects and significance in separation and purification systems.
Topics: Silicon Dioxide; Muramidase; Microspheres; Chromatography, Ion Exchange; Metals, Heavy; Adsorption; Chromatography, High Pressure Liquid; Particle Size; Surface Properties; Water Pollutants, Chemical
PubMed: 38819781
DOI: 10.1002/jssc.202400126 -
Bioconjugate Chemistry Jun 2024Bioconjugation of polymers to proteins is a method to impart improved stability and pharmacokinetic properties to biologic systems. However, the precise effects of... (Comparative Study)
Comparative Study
Bioconjugation of polymers to proteins is a method to impart improved stability and pharmacokinetic properties to biologic systems. However, the precise effects of polymer architecture on the resulting bioconjugates are not well understood. Particularly, cyclic polymers are known to possess unique features such as a decreased hydrodynamic radius when compared to their linear counterparts of the same molecular weight, but have not yet been studied. Here, we report the first bioconjugation of a cyclic polymer, poly(ethylene glycol) (PEG), to a model protein, T4 lysozyme, containing a single engineered cysteine residue (V131C). We compare the stability and activity of this conjugate with those of a linear PEG-T4 lysozyme analogue of similar molecular weight. Furthermore, we used molecular dynamics (MD) simulations to determine the behavior of the polymer-protein conjugates in solution. We introduce cyclic polymer-protein conjugates as potential candidates for the improvement of biologic therapeutics.
Topics: Polyethylene Glycols; Muramidase; Molecular Dynamics Simulation; Bacteriophage T4
PubMed: 38809040
DOI: 10.1021/acs.bioconjchem.4c00202 -
Nutrients May 2024Human milk (HM) contains the essential macronutrients and bioactive compounds necessary for the normal growth and development of newborns. The milk collected by human...
Human milk (HM) contains the essential macronutrients and bioactive compounds necessary for the normal growth and development of newborns. The milk collected by human milk banks is stored frozen and pasteurized, reducing its nutritional and biological value. The purpose of this study was to determine the effect of hyperbaric storage at subzero temperatures (HS-ST) on the macronutrients and bioactive proteins in HM. As control samples, HM was stored at the same temperatures under 0.1 MPa. A Miris HM analyzer was used to determine the macronutrients and the energy value. The lactoferrin (LF), lysozyme (LYZ) and lactalbumin (LAC) content was checked using high-performance liquid chromatography, and an ELISA test was used to quantify secretory immunoglobulin A (sIgA). The results showed that the macronutrient content did not change significantly after 90 days of storage at 60 MPa/-5 °C, 78 MPa/-7 °C, 111 MPa/-10 °C or 130 MPa/-12 °C. Retention higher than 90% of LYZ, LAC, LF and sIgA was observed in the HM stored at conditions of up to 111 MPa/-10 °C. However, at 130 MPa/-12 °C, there was a reduction in LYZ and LF, by 39 and 89%, respectively. The storage of HM at subzero temperatures at 0.1 MPa did not affect the content of carbohydrates or crude and true protein. For fat and the energy value, significant decreases were observed at -5 °C after 90 days of storage.
Topics: Humans; Milk, Human; Nutritive Value; Lactoferrin; Food Storage; Muramidase; Lactalbumin; Immunoglobulin A, Secretory; Nutrients; Milk Proteins; Female
PubMed: 38794693
DOI: 10.3390/nu16101455 -
ACS Applied Materials & Interfaces Jun 2024Protein adsorption on solid surfaces is a process relevant to biological, medical, industrial, and environmental applications. Despite this wide interest and advancement...
Protein adsorption on solid surfaces is a process relevant to biological, medical, industrial, and environmental applications. Despite this wide interest and advancement in measurement techniques, the complexity of protein adsorption has frustrated its accurate prediction. To address this challenge, here, data regarding protein adsorption reported in the last four decades was collected, checked for completeness and correctness, organized, and archived in an upgraded, freely accessible Biomolecular Adsorption Database, which is equivalent to a large-scale, ad hoc, crowd-sourced multifactorial experiment. The shape and physicochemical properties of the proteins present in the database were quantified on their molecular surfaces using an in-house program (ProMS) operating as an add-on to the PyMol software. Machine learning-based analysis indicated that protein adsorption on hydrophobic and hydrophilic surfaces is modulated by different sets of operational, structural, and molecular surface-based physicochemical parameters. Separately, the adsorption data regarding four "benchmark" proteins, i.e., lysozyme, albumin, IgG, and fibrinogen, was processed by piecewise linear regression with the protein monolayer acting as breakpoint, using the linearization of the Langmuir isotherm formalism, resulting in semiempirical relationships predicting protein adsorption. These relationships, derived separately for hydrophilic and hydrophobic surfaces, described well the protein concentration on the surface as a function of the protein concentration in solution, adsorbing surface contact angle, ionic strength, pH, and temperature of the carrying fluid, and the difference between pH and the isoelectric point of the protein. When applying the semiempirical relationships derived for benchmark proteins to two other "test" proteins with known PDB structure, i.e., β-lactoglobulin and α-lactalbumin, the errors of this extrapolation were found to be in a linear relationship with the dissimilarity between the benchmark and the test proteins. The work presented here can be used for the estimation of operational parameters modulating protein adsorption for various applications such as diagnostic devices, pharmaceuticals, biomaterials, or the food industry.
Topics: Adsorption; Surface Properties; Hydrophobic and Hydrophilic Interactions; Data Mining; Proteins; Muramidase; Databases, Protein; Machine Learning
PubMed: 38787331
DOI: 10.1021/acsami.4c06759 -
Gut Microbes 2024Chemotherapy remains a major treatment for malignant tumors, yet the application of standard dose intensity chemotherapy is limited due to the side effects of cytotoxic...
Chemotherapy remains a major treatment for malignant tumors, yet the application of standard dose intensity chemotherapy is limited due to the side effects of cytotoxic drugs, especially in old populations. The underlying mechanisms of cytotoxicity and strategies to increase the safety and tolerance of chemotherapy remain to be explored. Using 5-fluorouracil (5-FU), a cornerstone chemotherapeutic drug, we demonstrate that the main cause of death in (AL) fed mice after 5-FU chemotherapy was infection caused by translocation of intestinal opportunistic pathogens. We show that these opportunistic pathogens greatly increase in the intestine after chemotherapy, which was closely related to loss of intestinal lysozyme. Of note, two weeks of dietary restriction (DR) prior to chemotherapy significantly protected the loss of lysozyme and increased the content of the beneficial genera, resulting in a substantial inhibition of intestinal opportunistic pathogens and their translocation. The rescue effect of DR could be mimicked by Lysozyme or gavage. Our study provides the first evidence that DR achieved a comprehensive protection of the intestinal physical, biological and chemical barriers, which significantly improved the overall survival of 5-FU-treated mice. Importantly, the above findings were more prominent in old mice. Furthermore, we show that patients over 65 years old have enriched opportunistic pathogens in their gut microbiota, especially after 5-FU based chemotherapy. Our study reveals important mechanisms for the poor chemotherapy tolerance of the elderly population, which can be significantly improved by short-term DR. This study generates new insights into methods for improving the chemotherapeutic prognosis by increasing the chemotherapy tolerance and safety of patients with malignant tumors.
Topics: Animals; Fluorouracil; Mice; Bacterial Translocation; Gastrointestinal Microbiome; Humans; Intestines; Muramidase; Caloric Restriction; Mice, Inbred C57BL; Male; Lactobacillus; Bacteria; Female; Opportunistic Infections
PubMed: 38780487
DOI: 10.1080/19490976.2024.2355693 -
Neuroscience Letters Jun 2024Alzheimer's disease (AD) is a prevalent form of dementia in the elderly. There is currently no effective treatment available for this disease. Diagnosis of AD typically...
Altering plasma lipids and liver enzyme activities via hippocampal injections of hen Lysozyme amyloid aggregates in an Alzheimer's disease mouse model: Insights into the therapeutic role of Bis (Indolyl) phenylmethane.
Alzheimer's disease (AD) is a prevalent form of dementia in the elderly. There is currently no effective treatment available for this disease. Diagnosis of AD typically relies on clinical manifestations and specific biomarkers. The present study investigated the impact of inducing Alzheimer's disease (AD) in mice through the injection of lysozyme amyloids formed in the presence or absence of Bis (Indolyl) phenylmethane (BIPM) on alterations in plasma lipid profiles and liver enzyme activities. 24 adult Wistar rats were divided into control, Scopolamine, Lysozyme, BIPM groups and the blood samples were obtained from the groups for biochemical analysis. The findings of the study revealed significant changes in the plasma lipid profiles and liver enzyme markers of the Lysozyme group compared to the control group. The Lysozyme group exhibited elevated triglycerides (n = 6, P < 0.02) and LDL levels (n = 6, P < 0.02), reduced HDL (n = 6, P < 0.05) and cholesterol levels (n = 6, P < 0.02), and altered serum glutamic oxaloacetic transaminase (SGOT) level (n = 6, P < 0.05) compared to controls. While the level of serum glutamic pyruvic transaminase (SGPT) did not change significantly compared to the control. BIPM groups showed no significant changes in lipid or enzyme levels compared to controls. Overall, our research has shown that BIPM has the ability to modify the structure of HEWL aggregates, thereby improving the detrimental effects associated with AD caused by these aggregates. Analyzing lipid profiles and liver enzyme markers presents a promising avenue for targeted therapeutic approaches. These alterations observed in the plasma may potentially serve as candidate biomarkers for diagnosing this disease.
Topics: Animals; Alzheimer Disease; Liver; Muramidase; Hippocampus; Rats, Wistar; Lipids; Disease Models, Animal; Mice; Male; Indoles; Amyloid; Rats
PubMed: 38768939
DOI: 10.1016/j.neulet.2024.137825