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Animal Biotechnology Nov 2024NK-lysins from chicken, bovine and human are used as antiviral and antibacterial agents. Gram-negative and gram-positive microorganisms, including and , are susceptible...
NK-lysins from chicken, bovine and human are used as antiviral and antibacterial agents. Gram-negative and gram-positive microorganisms, including and , are susceptible to NK-lysin treatment. The presence of dominant TEM-1 gene was noted in all untreated and treated bacteria, while TOHO-1 gene was absent in all bacteria. Importantly, β-lactamase genes CTX-M-1, CTX-M-8, and CTX-M-9 genes were detected in untreated bacterial strains; however, none of these were found in any bacterial strains following treatment with NK-lysin peptides. NK-lysin peptides are also used to test for inhibition of infectivity, which ranged from 50 to 90% depending on NK-lysin species. Chicken, bo vine and human NK-lysin peptides are demonstrated herein to have antibacterial activity and antiviral activity against Rotavirus (strain SA-11). On the basis of the comparison between these peptides, potent antiviral activity of bovine NK-lysin against Rotavirus (strain SA-11) is particularly evident, inhibiting infection by up to 90%. However, growth was also significantly inhibited by chicken and human NK-lysin peptides, restricted by 80 and 50%, respectively. This study provided a novel treatment using NK-lysin peptides to inhibit expression of β-lactamase genes in β-lactam antibiotic-resistant bacterial infections.
Topics: Animals; Cattle; Humans; Anti-Bacterial Agents; Drug Resistance, Bacterial; Peptides; beta-Lactamases; Escherichia coli; Antiviral Agents; Proteolipids
PubMed: 38100547
DOI: 10.1080/10495398.2023.2290520 -
Journal of Visualized Experiments : JoVE Mar 2021Membrane proteins are vital for cell function and thus represent important drug targets. Solid-state Nuclear Magnetic Resonance (ssNMR) spectroscopy offers a unique...
Membrane proteins are vital for cell function and thus represent important drug targets. Solid-state Nuclear Magnetic Resonance (ssNMR) spectroscopy offers a unique access to probe the structure and dynamics of such proteins in biological membranes of increasing complexity. Here, we present modern solid-state NMR spectroscopy as a tool to study structure and dynamics of proteins in natural lipid membranes and at atomic scale. Such spectroscopic studies profit from the use of high-sensitivity ssNMR methods, i.e., proton-(H)-detected ssNMR and DNP (Dynamic Nuclear Polarization) supported ssNMR. Using bacterial outer membrane beta-barrel protein BamA and the ion channel KcsA, we present methods to prepare isotope-labeled membrane proteins and to derive structural and motional information by ssNMR.
Topics: Bacterial Proteins; Cell Membrane; Inclusion Bodies; Isotope Labeling; Membrane Proteins; Nuclear Magnetic Resonance, Biomolecular; Point Mutation; Potassium Channels; Protein Refolding; Proteolipids; Protons; Staining and Labeling
PubMed: 33749679
DOI: 10.3791/62197 -
Scientific Reports Feb 2022Malignant melanoma is the main cause of death in patients with skin cancer. Overexpression of Proteolipid protein 2 (PLP2) increased tumor metastasis and the knockdown...
Malignant melanoma is the main cause of death in patients with skin cancer. Overexpression of Proteolipid protein 2 (PLP2) increased tumor metastasis and the knockdown of PLP2 inhibited the growth and metastasis of melanoma cells. In the present work, we studied the antitumor activity of peptide Rb4 derived from protein PLP2. In vitro, Rb4 induced F-actin polymerization, prevented F-actin depolymerization and increased the ER-derived cytosolic calcium. Such effects were associated with necrosis of murine melanoma B16F10-Nex2 cells and with inhibition of the viability of human cancer cell lines. Loss of plasma membrane integrity, dilation of mitochondria, cytoplasm vacuolation and absence of chromatin condensation characterized tumor cell necrosis. Cleavage of PARP-1 and inhibition of RIP1 expression were also observed. In vivo, peptide Rb4 reduced the lung metastasis of tumor cells and delayed the subcutaneous melanoma growth in a syngeneic model. Rb4 induced the expression of two DAMPs molecules, HMGB1 and calreticulin, in B16F10-Nex2. Our results suggest that peptide Rb4 acts directly on tumor cells inducing the expression of DAMPs, which trigger the immunoprotective effect in vivo against melanoma cells. We suggest that peptide Rb4 is a promising compound to be developed as an anticancer drug.
Topics: Animals; Antineoplastic Agents; Calreticulin; Cell Death; Cell Line, Tumor; Gene Expression; HMGB1 Protein; Humans; MARVEL Domain-Containing Proteins; Melanoma; Mice; Necrosis; Nuclear Pore Complex Proteins; Peptides; Poly (ADP-Ribose) Polymerase-1; Proteolipids; RNA-Binding Proteins; Skin Neoplasms
PubMed: 35190586
DOI: 10.1038/s41598-022-06429-8 -
BMC Biology Feb 2024Membranes are protein and lipid structures that surround cells and other biological compartments. We present a conceptual model wherein all membranes are organized into...
Membranes are protein and lipid structures that surround cells and other biological compartments. We present a conceptual model wherein all membranes are organized into structural and functional zones. The assembly of zones such as receptor clusters, protein-coated pits, lamellipodia, cell junctions, and membrane fusion sites is explained to occur through a protein-lipid code. This challenges the theory that lipids sort proteins after forming stable membrane subregions independently of proteins.
Topics: Proteolipids; Membranes; Carrier Proteins; Cell Membrane
PubMed: 38414038
DOI: 10.1186/s12915-024-01849-6 -
Methods in Molecular Biology (Clifton,... 2018Nucleic acid aptamers are therapeutic agents consisting of short single-strand DNA or RNA oligonucleotides, which have the ability to bind to target therapeutic...
Nucleic acid aptamers are therapeutic agents consisting of short single-strand DNA or RNA oligonucleotides, which have the ability to bind to target therapeutic molecules with high affinity and specificity, and have been developed as potent drugs for the treatment of rheumatoid arthritis. Aptamers have unique and advantageous features over antibodies, such as superior affinity with nano- or pico-molar dissociation constants, and ease of chemical synthesis, modification, and inactivation by designing antisense sequences. In this chapter, using a DNA-oligonucleotide pool, the technology of proteoliposome-systematic evolution of ligands by exponential enrichment (SELEX) is introduced. By using this technique, potential therapeutic agents with high affinity and specificity could be obtained.
Topics: Aptamers, Nucleotide; DNA, Single-Stranded; Oligonucleotides; Proteolipids; SELEX Aptamer Technique
PubMed: 30244458
DOI: 10.1007/978-1-4939-8802-0_11 -
Current Pharmaceutical Design 2017Transport systems are hydrophobic proteins localized in cell membranes where they mediate transmembrane flow of nutrients, ions and any other compounds essential for... (Review)
Review
Transport systems are hydrophobic proteins localized in cell membranes where they mediate transmembrane flow of nutrients, ions and any other compounds essential for cell metabolism. More than 400 transporters of the SoLuteCarrier (SLC) group are present in human cells. Transporters take contacts also with xenobiotics, thus mediating absorption and/or interaction with these exogenous compounds. Since drugs belong to xenobiotics, transporters gained interest also in drug discovery. Transporters differentially expressed in pathological conditions are exploited as drug targets. Among the methodologies for defining drug interactions, in silico ligand screening and intact cell transport assay were the most diffused, so far. The first is a predictive methodology based on docking chemicals to transporters. It presents limitations due to the small number of human transporter 3D structures that have to be constructed by homology modeling. Intact cells are used for testing effects of drugs and for validating predictions. The challenges of handling this very complex experimental system, are the interferences caused by other transporters and/or intracellular enzymes. Thus, methodologies with lower complexity are welcome. One of the most updated is the proteoliposome nanotechnology consisting in a cell mimicking phospholipid membrane in which a purified transporter is inserted. In this system, drug-transporter interaction can be studied defining kinetics and mechanisms. Several data have been obtained by proteoliposome nanotechnology. An overview of data obtained on the organic cation transporters OCTN1, OCTN2 and on the amino acid transporters ASCT2 and B0AT1 will be presented. Standardized procedures, expected to be pointed out, will enlarge the assay to High Throughput Screenings.
Topics: Animals; Biological Transport; Cell Membrane; Food; Humans; Membrane Transport Proteins; Nanotechnology; Protein Binding; Protein Structure, Secondary; Proteolipids
PubMed: 28625135
DOI: 10.2174/1381612823666170616083705 -
Critical Reviews in Biochemistry and... 2015Proteoliposomes have been widely used for in vitro studies of membrane fusion mediated by synaptic proteins. Initially, such studies were made with large unsynchronized... (Review)
Review
Proteoliposomes have been widely used for in vitro studies of membrane fusion mediated by synaptic proteins. Initially, such studies were made with large unsynchronized ensembles of vesicles. Such ensemble assays limited the insights into the SNARE-mediated fusion mechanism that could be obtained from them. Single particle microscopy experiments can alleviate many of these limitations but they pose significant technical challenges. Here we summarize various approaches that have enabled studies of fusion mediated by SNAREs and other synaptic proteins at a single-particle level. Currently available methods are described and their advantages and limitations are discussed.
Topics: Animals; Cytological Techniques; Fluorescence Resonance Energy Transfer; Humans; In Vitro Techniques; Membrane Fusion; Proteolipids; SNARE Proteins; Synaptic Vesicles
PubMed: 25788028
DOI: 10.3109/10409238.2015.1023252 -
Cellular and Molecular Life Sciences :... Apr 2022Proteolipids are proteins with unusual lipid-like properties. It has long been established that PLP and plasmolipin, which are two unrelated membrane-tetra-spanning...
Proteolipids are proteins with unusual lipid-like properties. It has long been established that PLP and plasmolipin, which are two unrelated membrane-tetra-spanning myelin proteolipids, can be converted in vitro into a water-soluble form with a distinct conformation, raising the question of whether these, or other similar proteolipids, can adopt two different conformations in the cell to adapt their structure to distinct environments. Here, we show that MALL, another proteolipid with a membrane-tetra-spanning structure, distributes in membranes outside the nucleus and, within the nucleus, in membrane-less, liquid-like PML body biomolecular condensates. Detection of MALL in one or other environment was strictly dependent on the method of cell fixation used, suggesting that MALL adopts different conformations depending on its physical environment -lipidic or aqueous- in the cell. The acquisition of the condensate-compatible conformation requires PML expression. Excess MALL perturbed the distribution of the inner nuclear membrane proteins emerin and LAP2β, and that of the DNA-binding protein BAF, leading to the formation of aberrant nuclei. This effect, which is consistent with studies identifying overexpressed MALL as an unfavorable prognostic factor in cancer, could contribute to cell malignancy. Our study establishes a link between proteolipids, membranes and biomolecular condensates, with potential biomedical implications.
Topics: Biomolecular Condensates; Cell Nucleus; Humans; Molecular Conformation; Neoplasms; Proteolipids
PubMed: 35399121
DOI: 10.1007/s00018-022-04270-w -
Protein Expression and Purification Jul 2019Human P-glycoprotein (P-gp) is an ATP-binding cassette transporter that has been implicated in altering the pharmacokinetics of anticancer drugs in normal tissues and...
Human P-glycoprotein (P-gp) is an ATP-binding cassette transporter that has been implicated in altering the pharmacokinetics of anticancer drugs in normal tissues and development of multidrug resistance in tumor cells via drug efflux. There is still no definitive explanation of the mechanism by which P-gp effluxes drugs. One of the challenges of large-scale purification of membrane transporters is the selection of a suitable detergent for its optimal extraction from cell membranes. In addition, further steps of purification can often lead to inactivation and aggregation, decreasing the yield of purified protein. Here we report the large-scale purification of human P-gp expressed in High-Five insect cells using recombinant baculovirus. The purification strategies we present yield homogeneous functionally active wild type P-gp and its E556Q/E1201Q mutant, which is defective in carrying out ATP hydrolysis. Three detergents (1,2-diheptanoyol-sn-glycero-3-phosphocholine, dodecyl maltoside and n-octyl-β-d-glucopyranoside) were used to solubilize and purify P-gp from insect cell membranes. P-gp purification was performed first using immobilized metal affinity chromatography, then followed by a second step of either anion exchange chromatography or size exclusion chromatography to yield protein in concentrations of 2-12 mg/mL. Size exclusion chromatography was the preferred method, as it allows separation of monomeric transporters from aggregates. We show that the purified protein, when reconstituted in proteoliposomes and nanodiscs, exhibits both basal and substrate or inhibitor-modulated ATPase activity. This report thus provides a convenient and robust method to obtain large amounts of active homogeneously purified human P-gp that is suitable for biochemical, biophysical and structural characterization.
Topics: ATP Binding Cassette Transporter, Subfamily B; Baculoviridae; Cell Extracts; Chromatography, Liquid; Detergents; Escherichia coli; Glucosides; Humans; Phospholipids; Proteolipids; Recombinant Proteins
PubMed: 30851394
DOI: 10.1016/j.pep.2019.03.002 -
Science Advances Mar 2023The cytoskeletal proteins tubulin and actin are the obligate substrates of TCP-1 ring complex/Chaperonin containing TCP-1 (TRiC/CCT), and their folding involves...
The cytoskeletal proteins tubulin and actin are the obligate substrates of TCP-1 ring complex/Chaperonin containing TCP-1 (TRiC/CCT), and their folding involves co-chaperone. Through cryo-electron microscopy analysis, we present a more complete picture of TRiC-assisted tubulin/actin folding along TRiC adenosine triphosphatase cycle, under the coordination of co-chaperone plp2. In the open S1/S2 states, plp2 and tubulin/actin engaged within opposite TRiC chambers. Notably, we captured an unprecedented TRiC-plp2-tubulin complex in the closed S3 state, engaged with a folded full-length -tubulin and loaded with a guanosine triphosphate, and a plp2 occupying opposite rings. Another closed S4 state revealed an actin in the intermediate folding state and a plp2. Accompanying TRiC ring closure, plp2 translocation could coordinate substrate translocation on the CCT6 hemisphere, facilitating substrate stabilization and folding. Our findings reveal the folding mechanism of the major cytoskeletal proteins tubulin/actin under the coordination of the biogenesis machinery TRiC and plp2 and extend our understanding of the links between cytoskeletal proteostasis and related human diseases.
Topics: Humans; Actins; Cryoelectron Microscopy; MARVEL Domain-Containing Proteins; Molecular Chaperones; Protein Folding; Proteolipids; Tubulin; Cytoskeletal Proteins
PubMed: 36921056
DOI: 10.1126/sciadv.ade1207