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Topic Review
Endogenous Metal Nanoparticles in Biological Systems
The blood and tissues of vertebrate animals and mammals contain small endogenous metal nanoparticles. These nanoparticles were observed to be composed of individual atoms of iron, copper, zinc, silver, gold, platinum, and other metals. Metal nanoparticles can bind proteins and produce proteinaceous particles called proteons. A small fraction of the entire pool of nanoparticles is usually linked with proteins to form proteons. These endogenous metal nanoparticles, along with engineered zinc and copper nanoparticles at subnanomolar levels, were shown to be lethal to cultured cancer cells. These nanoparticles appear to be elemental crystalline metal nanoparticles. It was discovered that zinc nanoparticles produce no odor response but increase the odor reaction if mixed with an odorant. Some other metal nanoparticles, including copper, silver, gold, and platinum nanoparticles, do not affect the responses to odorants. The sources of metal nanoparticles in animal blood and tissues may include dietary plants and gut microorganisms. The solid physiological and biochemical properties of metal nanoparticles reflect their importance in cell homeostasis and disease.
  • 1.1K
  • 05 Nov 2021
Topic Review
Human SRC Homology 3 Domains
SRC homology 3 (SH3) domains are fundamental modules that enable the assembly of protein complexes through physical interactions with a pool of proline-rich/noncanonical motifs from partner proteins. They are widely studied modular building blocks across all five kingdoms of life and viruses, mediating various biological processes. The SH3 domains are also implicated in the development of human diseases, such as cancer, leukemia, osteoporosis, Alzheimer’s disease, and various infections.
  • 1.1K
  • 16 Aug 2023
Topic Review
Genetically Encoded Biosensors for O2 and ROS Detection
The intracellular concentrations of oxygen and reactive oxygen species (ROS) in living cells represent critical information for investigating physiological and pathological conditions. Real-time measurement often relies on genetically encoded proteins that are responsive to fluctuations in either oxygen or ROS concentrations. The direct binding or chemical reactions that occur in their presence either directly alter the fluorescence properties of the binding protein or alter the fluorescence properties of fusion partners, mostly consisting of variants of the green fluorescent protein. Oxygen sensing takes advantage of several mechanisms, including (i) the oxygen-dependent hydroxylation of a domain of the hypoxia-inducible factor-1, which, in turn, promotes its cellular degradation along with fluorescent fusion partners; (ii) the naturally oxygen-dependent maturation of the fluorophore of green fluorescent protein variants; and (iii) direct oxygen binding by proteins, including heme proteins, expressed in fusion with fluorescent partners, resulting in changes in fluorescence due to conformational alterations or fluorescence resonance energy transfer. 
  • 1.1K
  • 06 Nov 2023
Topic Review
Pod Photosynthetic
Increasing photosynthetic ability as a whole is essential for acquiring higher crop yields. Nonleaf green organs (NLGOs) make important contributions to photosynthate formation, especially under stress conditions.In the present study, the experiment is designed for alfalfa (Medicago sativa) under drought stress to explore the photosynthetic responses of pod walls after 5, 10, 15, and 20 days of pollination (DAP5, DAP10, DAP15, and DAP20) based on ultrastructural, physiological and proteomic analyses. Stomata were evidently observed on the outer epidermis of the pod wall. Chloroplasts had intact structures arranged alongside the cell wall, which on DAP5 were already capable of producing photosynthate. The pod wall at the late stage (DAP20) still had photosynthetic ability under well-watered (WW) treatments, while under water-stress (WS), the structure of the chloroplast membrane was damaged and the grana lamella of thylakoids were blurry. The chlorophyll a and chlorophyll b concentrations both decreased with the development of pod walls, and drought stress impeded the synthesis of photosynthetic pigments. Although the activity of ribulose-1,5-bisphosphate carboxylase (RuBisCo) decreased in the pod wall under drought stress, the activity of phosphoenolpyruvate carboxylase (PEPC) increased higher than that of RuBisCo. The proteomic analysis showed that the absorption of light is limited due to the suppression of the synthesis of chlorophyll a/b binding proteins by drought stress. Moreover, proteins involved in photosystem I and photosystem II were downregulated under WW compared with WS. Although the expression of some proteins participating in the regeneration period of RuBisCo was suppressed in the pod wall subjected to drought stress, the synthesis of PEPC was induced. In addition, some proteins, which were involved in the reduction period of RuBisCo, carbohydrate metabolism, and energy metabolism, and related to resistance, including chitinase, heat shock protein 81-2 (Hsp81-2), and lipoxygenases (LOXs), were highly expressed for the protective response to drought stress. It could be suggested that the pod wall in alfalfa is capable of operating photosynthesis and reducing the photosynthetic loss from drought stress through the promotion of the C4 pathway, ATP synthesis, and resistance ability.
  • 1.1K
  • 27 Oct 2020
Topic Review
Yeast Heterologous Expression Systems Study Plant Membrane Proteins
Researchers are often interested in proteins that are present in cells in small ratios compared to the total amount of proteins. These proteins include transcription factors, hormones and specific membrane proteins. However, sufficient amounts of well-purified protein preparations are required for functional and structural studies of these proteins, including the creation of artificial proteoliposomes and the growth of protein 2D and 3D crystals. This aim can be achieved by the expression of the target protein in a heterologous system. The most popular for heterologous protein expression are the two species, baker’s yeast S. cerevisiae and methylotrophic yeast P. pastoris, expression in which is a well-established and widely used technique. 
  • 1.1K
  • 26 Jul 2023
Topic Review
Textile Electrodes for Wearable Biopotential Signal Monitoring
The technology of wearable medical equipment has advanced to the point where it is now possible to monitor the electrocardiogram and electromyogram comfortably at home. The transition from wet Ag/AgCl electrodes to various types of gel-free dry electrodes has made it possible to continuously and accurately monitor the biopotential signals. Fabrics or textiles, which were once meant to protect the human body, have undergone significant development and are now employed as intelligent textile materials for healthcare monitoring. The conductive textile electrodes provide the benefit of being breathable and comfortable.
  • 1.1K
  • 11 Aug 2023
Topic Review
Serum Albumin for Magnetic Nanoparticles Coating
Magnetic nanoparticles (MNPs) have great potential in biochemistry and medical science. In particular, iron oxide nanoparticles have demonstrated a promising effect in various biomedical applications due to their high magnetic properties, large surface area, stability, and easy functionalization. However, colloidal stability, biocompatibility, and potential toxicity of MNPs in physiological environments are crucial for their in vivo application. In this context, many research articles focused on the possible procedures for MNPs coating to improve their physic-chemical and biological properties. The fabrication strategy of biocompatible iron oxide nanoparticles using human serum albumin (HSA) is viable. HSA is mainly a transport protein with many functions in various fundamental processes. It is a highly potential candidate for nanoparticles coating and theranostics area and can provide biocompatibility, prolonged blood circulation, and possibly resolve the drug-resistance cancer problem. 
  • 1.1K
  • 10 Mar 2022
Topic Review
Nanomaterials in Cancer Therapy
This entry analyzed the different roles of nanomaterials, such as contrast agent and dose enhancer, in biomedical imaging and cancer therapy. Moreover, the review discussed the underlying mechanisms of nanomaterials including physical, chemical, and biological mechanisms. Some new applications of nanomaterials as theranostic agents are explored. Through a thorough understanding of the recent advances in nanomaterial application in biomedical imaging and cancer therapy, we identified new directions for the optimization and clinical transformation of nanomaterials.
  • 1.1K
  • 08 Feb 2021
Topic Review
Intrinsically Disordered Proteins
Intrinsically disordered proteins (IDPs) do not have rigid 3D structures, showing changes in their folding depending on the environment or ligands. Intrinsically disordered proteins are widely spread in eukaryotic genomes, and these proteins participate in many cell regulatory metabolism processes. Some IDPs, when aberrantly folded, can be the cause of some diseases such as Alzheimer′s, Parkinson′s, and prionic, among others. In these diseases, there are modifications in parts of the protein or in its entirety.
  • 1.1K
  • 22 Apr 2022
Topic Review
Oxidative Crosslinking of Peptides and Proteins
Covalent crosslinks within or between proteins play a key role in determining the structure and function of proteins. Some of these are formed intentionally by either enzymatic or molecular reactions and are critical to normal physiological function. Others are generated as a consequence of exposure to oxidants (radicals, excited states or two-electron species) and other endogenous or external stimuli, or as a result of the actions of a number of enzymes (e.g., oxidases and peroxidases). Increasing evidence indicates that the accumulation of unwanted crosslinks, as is seen in ageing and multiple pathologies, has adverse effects on biological function.
  • 1.1K
  • 24 Feb 2022
Topic Review
Applications of Strain-Amplification Techniques with α-Synuclein
α-Synuclein (αS) is remarkable for both its extensive conformational plasticity and pathologic prion-like properties. A fundamental understanding of αS’ conformational properties has been translated to the development of strain amplification technologies, which have provided further insight into the role of specific strains in distinct α-synucleinopathies, and show promise for the early diagnosis of disease. Strain amplification assays, protein misfolding cyclic amplification (PMCA) and real-time quaking-induced conversion (RT-QuIC), are powerful emerging techniques that can detect misfolded αS to diagnose and differentiate synucleinopathies.
  • 1.0K
  • 27 Jul 2022
Topic Review
Reentry Arrhythmia in Cardiac Tissue Models
Cardiac arrhythmias are a major cause of cardiovascular mortality worldwide. Many arrhythmias are caused by reentry, a phenomenon where excitation waves circulate in the heart. Optical mapping techniques have revealed the role of reentry in arrhythmia initiation and fibrillation transition, but the underlying biophysical mechanisms are still difficult to investigate in intact hearts.
  • 1.0K
  • 17 Oct 2023
Topic Review
Emerging Pathogen-Detection Techniques in Agro-Food Sector
The agro-food sector is one of major contributors to the economy of a developing country. This sector offers a primary source of nutrition for livestock and also more than 80% of the food consumed by human beings. The monitoring of agro-food products is essential to maintain our civilization with food security via reducing the risk of infections. The diagnosis of pathogens can be carried out in plants themselves, in obtained food products, or in humans after the consumption of contaminated agro-foods.
  • 1.0K
  • 29 Jul 2022
Topic Review
Artificial Lipid Membranes for Viral Assembly Research
The cell plasma membrane is mainly composed of phospholipids, cholesterol and embedded proteins, presenting a complex interface with the cell environment. Enveloped viruses are also surrounded by a lipidic membrane derived from the host-cell membrane and acquired during the assembly at and the budding from the host cell plasma membrane. In this perspective, model membranes, composed of selected lipid mixtures mimicking plasma membrane chemical and physical properties, are tools of choice to decipher the first steps of enveloped viruses assembly. Hereafter are detailled some of the existing artificial lipid membranes and their contribution in deciphering the assembly process of 3 well known envelopped virus, the human immunodeficiency virus 1 (HIV-1), the Influenza virus (IfV) and the Ebola virus (EboV).
  • 1.0K
  • 29 Apr 2022
Topic Review
Water between Membrane and Colloidal Theories for Cells
To incorporate water as a structural and thermodynamic component of biomembranes, the consideration of the membrane interphase as a bidimensional hydrated polar head group solution, coupled to the hydrocarbon region allows for the reconciliation of two theories on cells in dispute today: one considering the membrane as an essential part in terms of compartmentalization, and another in which lipid membranes are not necessary and cells can be treated as a colloidal system. The criterium followed is to describe the membrane state as an open, non-autonomous and responsive system using the approach of Thermodynamic of Irreversible Processes. The concept of an open/non-autonomous membrane system allows for the visualization of the interrelationship between metabolic events and membrane polymorphic changes. Therefore, the Association Induction Hypothesis (AIH) and lipid properties interplay should consider hydration in terms of free energy modulated by water activity and surface (lateral) pressure.
  • 1.0K
  • 25 Aug 2022
Topic Review
Contributing Factors to Nuclear Mechanics
In eukaryotic cells, the nucleus houses the genomic material of the cell. The physical properties of the nucleus and its ability to sense external mechanical cues are tightly linked to the regulation of cellular events, such as gene expression. Nuclear mechanics and morphology are altered in many diseases such as cancer and premature ageing syndromes. Therefore, it is important to understand how different components contribute to nuclear processes, organisation and mechanics, and how they are misregulated in disease. Although, over the years, studies have focused on the nuclear lamina—a mesh of intermediate filament proteins residing between the chromatin and the nuclear membrane—there is growing evidence that chromatin structure and factors that regulate chromatin organisation are essential contributors to the physical properties of the nucleus.
  • 1.0K
  • 31 May 2021
Topic Review
Symptomatic Huntington’s Disease
This entry used a publically available dataset to perform in silico analysis using different bioinformatics tools (PathwayConnector, PathWalks, DyNet). The DEGs were identifed for the pre-symptomatic and symptomatic HD stages. The CACNA1I gene was the mostly highly rewired node among pre-symptomatic and symptomatic HD network. Prominent molecular pathways for each HD stage were then obtained, and metabolites related to each pathway for both disease stages were identified. The transforming growth factor beta (TGF- ) signaling (pre-symptomatic and symptomatic stages of the disease), calcium (Ca2+) signaling (pre-symptomatic), dopaminergic synapse pathway (symptomatic HD patients) and Hippo signaling (pre-symptomatic) pathways.  The genes, pathways and metabolites identified for each HD stage can provide a better understanding of the mechanisms that become altered in each disease stage. Our results can guide the development of therapies that may target the altered genes and metabolites of the perturbed pathways, leading to an improvement in clinical symptoms and hopefully a delay in the age of onset.
  • 1.0K
  • 20 Jan 2021
Topic Review
Motility of the Zoonotic Spirochete Leptospira
If a bacterium has motility, it will use the ability to survive and thrive. For many pathogenic species, their motilities are a crucial virulence factor. The form of motility varies among the species. Some use flagella for swimming in liquid, and others use the cell-surface machinery to move over solid surfaces. Spirochetes are distinguished from other bacterial species by their helical or flat wave morphology and periplasmic flagella (PFs). It is believed that the rotation of PFs beneath the outer membrane causes transformation or rolling of the cell body, propelling the spirochetes. Interestingly, some spirochetal species exhibit motility both in liquid and over surfaces, but it is not fully unveiled how the spirochete pathogenicity involves such amphibious motility.
  • 1.0K
  • 02 Mar 2022
Topic Review
Interfacial Adsorption of Bioengineered Monoclonal Antibodies
Monoclonal antibodies (mAbs) are an important class of biotherapeutics. MAbs, like any globular protein, are amphiphilic and readily adsorb to interfaces, potentially causing structural deformation and even unfolding. Desorption of structurally perturbed mAbs is often hypothesized to promote aggregation, potentially leading to the formation of subvisible particles and visible precipitates. Since mAbs are exposed to numerous interfaces during biomanufacturing, storage and administration, many studies have examined mAb adsorption to different interfaces under various mitigation strategies. 
  • 996
  • 05 Jan 2022
Topic Review
Prediction of Protein Stability Changes
Predicting protein stability changes upon genetic variations is still an open challenge. It is essential to understand the impact of the alterations in the amino acid sequence, mainly due to non-synonymous (or missense) DNA variations leading to the disruption or the enhancement of the protein activity, on human health and disease. In particular, protein stability perturbations have already been associated to pathogenic missense variants and they were shown to contribute to the loss of function in haploinsufficient genes.
  • 995
  • 02 Jul 2021
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