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Lipopeptide
A lipopeptide is a molecule consisting of a lipid connected to a peptide. They are able to self-assemble into different structures. Many bacteria produced these molecules as a part of their metabolism, especially those of the genus '' Bacillus'', '' Pseudomonas'' and '' Streptomyces''. Certain lipopeptides are used as antibiotics. Other lipopeptides are 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-spanning receptors usually expressed on sentinel cells such as macrophages and dendritic cells, that recogniz ... agonists. Certain lipopeptides can have strong antifungal and hemolytic activities. It has been demonstrated that their activity is generally linked to interactions with the plasma membrane, and sterol components of the plasma membrane could play a major role in this interaction. It is a general trend that adding a lipid group of a certain length (typically C10� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daptomycin
Daptomycin, sold under the brand name Cubicin among others, is a lipopeptide antibiotic used in the treatment of systemic and life-threatening infections caused by Gram-positive organisms. Daptomycin was removed from the World Health Organization's List of Essential Medicines in 2019. The World Health Organization classifies daptomycin as critically important for human medicine. Medical uses In the United States, daptomycin is indicated for use in adults for skin and skin structure infections caused by Gram-positive infections, ''S. aureus'' bacteraemia, and right-sided ''S. aureus'' endocarditis. It binds avidly to pulmonary surfactant, so cannot be used in the treatment of pneumonia. There seems to be a difference in working daptomycin on hematogenous pneumonia. Adverse effects Common adverse drug reactions associated with daptomycin therapy include: *Cardiovascular: low blood pressure, high blood pressure, swelling *Central nervous system: insomnia *Dermatological: ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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-spanning receptors usually expressed on sentinel cells such as macrophages and dendritic cells, that recognize structurally conserved molecules derived from 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. TLR1, TLR2, TLR4, TLR5, TLR6, and TLR10 are located on the cell membrane, whereas TLR3, TLR7, TLR8, and TLR9 are located in intracellular vesicles (because they are sensors of nucleic acids). TLRs received their name from their similarity to the protein coded by the toll gene. Function The ability of the immune s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycosubtilin
Mycosubtilin is a natural lipopeptide with antifungal and hemolytic activities and isolated from ''Bacillus'' species. It belongs to the iturin lipopeptide family. Definition Mycosubtilin is a natural lipopeptide. It is produced by the strains of ''Bacillus'' spp mainly by ''Bacillus subtilis''. It was discovered due to its antifungal activities. It belongs to the family of iturin lipopeptides Structure Mycosubtilin is a heptapeptide, cyclized in a ring with a β-amino fatty acid. The peptide sequence is composed of L-Asn-D-Tyr-D-Asn-L-Gln-L-Pro-D-Ser-L-Asn. The ramification of the β-amino fatty acid can be ''iso'' or ''anteiso'' . It could contain 16-17 carbon atom. Biological activities Mycosubtilin has strong antifungal and hemolytic activities. It is active against fungi and yeasts such as Candida albicans, Candida tropicalis, Saccharomyces cerevisiae, Penicillium notatum, Fusarium oxysporum ''Fusarium oxysporum'' (Schlecht as emended by Snyder and Hansen), an a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide
Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A polypeptide is a longer, continuous, unbranched peptide chain. Hence, peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. A polypeptide that contains more than approximately 50 amino acids is known as a protein. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, or 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacillus
''Bacillus'' (Latin "stick") is a genus of Gram-positive, rod-shaped bacteria, a member of the phylum '' Bacillota'', with 266 named species. The term is also used to describe the shape (rod) of other so-shaped bacteria; and the plural ''Bacilli'' is the name of the class of bacteria to which this genus belongs. ''Bacillus'' species can be either obligate aerobes which are dependent on oxygen, or facultative anaerobes which can survive in the absence of oxygen. Cultured ''Bacillus'' species test positive for the enzyme catalase if oxygen has been used or is present. ''Bacillus'' can reduce themselves to oval endospores and can remain in this dormant state for years. The endospore of one species from Morocco is reported to have survived being heated to 420 °C. Endospore formation is usually triggered by a lack of nutrients: the bacterium divides within its cell wall, and one side then engulfs the other. They are not true spores (i.e., not an offspring). Endospore fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surfactin
Surfactin is a very powerful surfactant commonly used as an antibiotic. It is a bacterial cyclic lipopeptide, largely prominent for its exceptional surfactant power. Its amphiphilic properties help this substance to survive in both hydrophilic and hydrophobic environments. It is an antibiotic produced by the Gram-positive endospore-forming bacteria ''Bacillus subtilis''. In the course of various studies of its properties, surfactin was found to exhibit effective characteristics like antibacterial, antiviral, antifungal, anti- mycoplasma and hemolytic activities. Structure and Synthesis The structure of the main congener consists of a peptide loop of seven amino acids ( L-glutamic acid, L-leucine, D-leucine, L-valine, L-aspartic acid, D-leucine and L-leucine) and a β-hydroxy fatty acid of variable length, thirteen to fifteen carbon atoms long. The glutamic acid and aspartic acid residues at positions 1 and 5 respectively, give the ring its hydrophilic character, as we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibiotics
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of such infections. They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity. Antibiotics are not effective against viruses such as the common cold or influenza; drugs which inhibit viruses are termed antiviral drugs or antivirals rather than antibiotics. Sometimes, the term ''antibiotic''—literally "opposing life", from the Greek roots ἀντι ''anti'', "against" and βίος ''bios'', "life"—is broadly used to refer to any substance used against microbes, but in the usual medical usage, antibiotics (such as penicillin) are those produced naturally (by one microorganism fighting another), whereas non-antibiotic antibacterials (such as sulfonamides and antise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caspofungin
Caspofungin ( INN) (brand name Cancidas) is a lipopeptide antifungal drug from Merck & Co., Inc. discovered by James Balkovec, Regina Black and Frances A. Bouffard. It is a member of a new class of antifungals termed the echinocandins. It works by inhibiting the enzyme (1→3)-β-D-glucan synthase and thereby disturbing the integrity of the fungal cell wall. Caspofungin was the first inhibitor of fungal (1→3)-β-D-glucan synthesis to be approved by the United States Food and Drug Administration. Caspofungin is administered intravenously. It is on the World Health Organization's List of Essential Medicines. Spectrum of Activity Caspofungin has been effective in treating fungal infections caused by ''Aspergillus'' and ''Candida'' species. It is a member of the echinocandin family, a new class of antifungal agents with broad spectrum of activity against all Candida species. In comparison to treatment with either fluconazole or Amphotericin B, all three drugs in this clas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pepducin
Pepducins are cell-penetrating peptides that act as intracellular modulators of signal transference from receptors to G proteins. Pepducins were first developed at the Tufts Medical Center laboratories of Dr. Athan Kuliopulos and Dr. Lidija Covic. Pepducins employ lipidated fragments of intracellular G protein-coupled receptor loops to modulate GPCR action in targeted cell-signaling pathways. A pepducin molecule consists of a short peptide derived from a GPCR intracellular loop tethered to a hydrophobic moiety. This structure allows pepducin lipopeptides to anchor in the cell membrane lipid bilayer and target the GPCR/G protein interface via a unique intracellular allosteric mechanism. Pepducins for over 15 different GPCRs have been successfully produced, several of which have shown activity in preclinical ''in vivo'' models. An anti- PAR4 pepducin extended bleeding time in mice and protected against systemic platelet activation and thrombosis. A CXCR4 agonist An agonist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibiotics
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of such infections. They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity. Antibiotics are not effective against viruses such as the common cold or influenza; drugs which inhibit viruses are termed antiviral drugs or antivirals rather than antibiotics. Sometimes, the term ''antibiotic''—literally "opposing life", from the Greek roots ἀντι ''anti'', "against" and βίος ''bios'', "life"—is broadly used to refer to any substance used against microbes, but in the usual medical usage, antibiotics (such as penicillin) are those produced naturally (by one microorganism fighting another), whereas non-antibiotic antibacterials (such as sulfonamides and antise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinocandins
Echinocandins are a class of antifungal drugs that inhibit the synthesis of β-glucan in the fungal cell wall via noncompetitive inhibition of the enzyme 1,3-β glucan synthase. The class has been termed the "penicillin of antifungals," along with the related papulacandins, as their mechanism of action resembles that of penicillin in bacteria. β-glucans are carbohydrate polymers that are cross-linked with other fungal cell wall components, the fungal equivalent to bacterial peptidoglycan. Caspofungin, micafungin, and anidulafungin are semisynthetic echinocandin derivatives with limited clinical use due to their solubility, antifungal spectrum, and pharmacokinetic properties. Medical uses Drugs and drug candidates in this class are fungicidal against some yeasts (most species of ''Candida'', but not '' Cryptococcus'', '' Trichosporon'', and '' Rhodotorula''). Echinocandins also have displayed activity against ''Candida'' biofilms, especially in synergistic activity with amph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GPCR
G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily-related proteins that are cell surface receptors that detect molecules outside the cell and activate cellular responses. Coupling with G proteins, they are called seven-transmembrane receptors because they pass through the cell membrane seven times. Text was copied from this source, which is available under Attribution 2.5 Generic (CC BY 2.5) license. Ligands can bind either to extracellular N-terminus and loops (e.g. glutamate receptors) or to the binding site within transmembrane helices (Rhodopsin-like family). They are all activated by agonists although a spontaneous auto-activation of an empty receptor can also be observed. G protein-coupled receptors are found only in eukaryotes, including yeast, choanoflagellates, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
