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Drosomycin
Drosomycin is an antifungal peptide from ''Drosophila melanogaster'' and was the first antifungal peptide isolated from insects. Drosomycin is induced by infection by the Toll signalling pathway, while expression in surface epithelia like the respiratory tract is instead controlled by the immune deficiency pathway (Imd). This means that drosomycin, alongside other antimicrobial peptides (AMPs) such as cecropins, diptericin, drosocin, metchnikowin and attacin, serves as a first line defence upon septic injury. However drosomycin is also expressed constitutively to a lesser extent in different tissues and throughout development. Structure Drosomycin is a 44-residue defensin-like peptide containing four disulfide bridges. These bridges stabilize a structure involving one α-helix and three β-sheets. Owing to these four disulfide bridges, drosomycin is resistant to degradation and the action of proteases. The cysteine stabilized αβ motif of drosomycin is also found in '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Toll-like Receptor
Toll-like receptors (TLRs) are a class of proteins that play a key role in the innate immune system. They are single-pass membrane protein, single-spanning receptor (biochemistry), receptors usually expressed on sentinel cells such as macrophages and dendritic cells, that recognize structurally conserved molecules derived from Microorganism, microbes. Once these microbes have reached physical barriers such as the skin or intestinal tract mucosa, they are recognized by TLRs, which activate immune cell responses. The TLRs include TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, TLR11, TLR12, and TLR13. Humans lack genes for TLR11, TLR12 and TLR13 and mice lack a functional gene for TLR10. The receptors TLR1, TLR2, TLR4, TLR5, TLR6, and TLR10 are located on the cell membrane, whereas TLR3, TLR7, TLR8, and TLR9 are located in Intracellular receptor, intracellular Vesicle (biology and chemistry), vesicles (because they are sensors of nucleic acids). TLRs received their name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Antifungal
An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as cryptococcal meningitis, and others. Such drugs are usually obtained by a doctor's prescription, but a few are available over the counter (OTC). The evolution of antifungal resistance is a growing threat to health globally. Routes of administration Ocular Indicated when the fungal infection is located in the eye. There is currently only one ocular antifungal available: natamycin. However, various other antifungal agents could be compounded in this formulation. Intrathecal Used occasionally when there's an infection of the central nervous system and other systemic options cannot reach the concentration required in that region for therapeutic benefit. Example(s): amphotericin B. Vaginal This may be used to treat some fungal in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Arthropod Defensin
Arthropod defensins are a family defensin proteins found in mollusks, insects, and arachnids. These cysteine-rich antibacterial peptides are primarily active against Gram-positive bacteria and fungi in vitro. However ''Drosophila'' fruit flies mutant for the fly defensin were more susceptible to infection by the Gram-negative bacteria '' Providencia burhodogranariea'', and resisted infection against Gram-positive bacteria like wild-type flies. It remains to be seen how in vitro activity relates to in vivo function. Mutants for the defensin-like antimicrobial peptide Drosomycin were more susceptible to fungi, validating a role for defensin-like peptides in anti-fungal defence. Structure Arthropod defensin peptides range in length from 38 to 51 amino acids. There are six conserved cysteines all involved in intrachain disulfide bonds. Studies have shown that the cysteine-bridge disulfide bonds are not required for antimicrobial activity, similar to findings in mammalian defensins. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Peptides
Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Dalton (unit), Da or more are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. Peptides fall under the broad chemical classes of biopolymer, biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligand (biochemistry), ligands such as coenzymes and cofactor (biochemistry), cofactors, to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed Residue (chemistry)#Biochemistry, residues. A water molecule is released during formation of each amide bond.. Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Spore Germination
Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, ferns, bacteria, and the growth of the pollen tube from the pollen grain of a seed plant. Seed plants Germination is usually the growth of a plant contained within a seed resulting in the formation of the seedling. It is also the process of reactivation of metabolic machinery of the seed resulting in the emergence of radicle and plumule. The seed of a vascular plant is a small package produced in a fruit or cone after the union of male and female reproductive cells. All fully developed seeds contain an embryo and, in most plant species some store of food reserves, wrapped in a seed coat. Dormant seeds are viable seeds that do not germinate because they require specific internal or environmental stimuli to resume growth. Under proper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Hypha
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or more cells surrounded by a tubular cell wall. In most fungi, hyphae are divided into cells by internal cross-walls called "septa" (singular septum). Septa are usually perforated by pores large enough for ribosomes, mitochondria, and sometimes nuclei to flow between cells. The major structural polymer in fungal cell walls is typically chitin, in contrast to plants and oomycetes that have cellulosic cell walls. Some fungi have aseptate hyphae, meaning their hyphae are not partitioned by septa. Hyphae have an average diameter of 4–6 μm. Growth Hyphae grow at their tips. During tip growth, cell walls are extended by the external assembly and polymerization of cell wall components, and the internal production of new cell membrane. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Lysis
Lysis ( ; from Greek 'loosening') is the breaking down of the membrane of a cell, often by viral, enzymic, or osmotic (that is, "lytic" ) mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a ''lysate''. In molecular biology, biochemistry, and cell biology laboratories, cell cultures may be subjected to lysis in the process of purifying their components, as in protein purification, DNA extraction, RNA extraction, or in purifying organelles. Many species of bacteria are subject to lysis by the enzyme lysozyme, found in animal saliva, egg white, and other secretions. Phage lytic enzymes (lysins) produced during bacteriophage infection are responsible for the ability of these viruses to lyse bacterial cells. Penicillin and related β-lactam antibiotics cause the death of bacteria through enzyme-mediated lysis that occurs after the drug causes the bacterium to form a defective cell wall. If the cell wall is completely lost and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Hermann Joseph Muller
Hermann Joseph Muller (December 21, 1890 – April 5, 1967) was an American geneticist who was awarded the 1946 Nobel Prize in Physiology or Medicine, "for the discovery that mutations can be induced by X-rays". Muller warned of long-term dangers of radioactive fallout from nuclear war and nuclear testing, which resulted in greater public scrutiny of these practices. Early life Muller was born in New York City, the son of Frances (Lyons) and Hermann Joseph Muller Sr., an artisan who worked with metals. Muller was a third-generation American whose father's ancestors were originally Catholic and came to the United States from Koblenz. His mother's family was of mixed Jewish (descended from Spanish and Portuguese Jews) and Anglican background, and had come from Britain. Among his first cousins was Alfred Kroeber (Kroeber was Ursula Le Guin's father) and first cousins once removed was Herbert J. Muller. As an adolescent, Muller attended a Unitarian church and considered himsel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Defensin
Defensins are small cysteine-rich cationic proteins across cellular life, including vertebrate and invertebrate animals, plants, and fungi. They are host defense peptides, with members displaying either direct Antimicrobial, antimicrobial activity, Immune system, immune signaling activities, or both. They are variously active against bacteria, fungus, fungi and many enveloped and nonenveloped viruses. They are typically 18-45 amino acids in length, with three or four highly conserved disulphide bonds. In animals, they are produced by cells of the innate immune system and epithelial cells, whereas in plants and fungi they are produced by a wide variety of tissues. An organism usually produces many different defensins, some of which are stored inside the cells (e.g. in neutrophil granulocytes to kill Phagocyte, phagocytosed bacteria), and others are secreted into the extracellular medium. For those that directly kill microbes, their mechanism of action varies from disruption of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Metchnikowin
Metchnikowin is a 26-residue antimicrobial peptide of the fruit fly ''Drosophila melanogaster'' that displays both antibacterial and antifungal properties. This peptide is expressed strongly in the ''Drosophila'' fat body (an organ similar to the human liver), but is also expressed at surface epithelia in the trachea and gut. This is regulated by the NF-κB signalling pathways Toll and Imd. Metchnikowin is named after Russian immunologist Élie Metchnikoff, one of the founders of modern immunology. Structure and function Metchnikowin has microbicidal activity against the gram-negative bacterium ''Escherichia coli'' and filamentous fungus ''Neurospora crassa'' at nanomolar concentrations. It is also one of the most abundant defence peptides in ''D. melanogaster'' following infection by the entomopathogenic fungus ''Beauveria bassiana''. Proline-rich peptides such as metchnikowin can bind to microbe ribosomes, preventing protein translation In biology, translation is the pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Attacin
Attacin is a glycine-rich protein of about 20 kDa belonging to the group of antimicrobial peptides (AMP). It is active against Gram-negative bacteria. Attacin was first discovered in ''Hyalophora cecropia ''Hyalophora cecropia'', the cecropia moth, is North America's largest native moth. It is a member of the family Saturniidae, or giant silk moths. Females have been documented with a wingspan of or more. These moths can be found predominately ac ...'', but is widely conserved in different insects from butterflies to fruit flies. See also * Diptericin, a structurally related antimicrobial peptide References {{Reflist Insect immunity Antimicrobial peptides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Peptide
Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Da or more are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. Peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed residues. A water molecule is released during formation of each amide bond.. All peptides except cyclic peptides have an N-terminal (amine group) and C-terminal (carboxyl g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
