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Lipopeptides
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 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–C12) to a lipopeptide will increase its bactericidal activity. Lipopeptides with a higher amount of carbon atoms, for example 14 or 16, in its lipid tail will typically have antibacterial activity as well as anti-fungal activity. Lipopeptide detergents (LPDs ... [...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] |
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 C-X-C chemokine r ... [...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 well as its ne ... [...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] |
Molecule
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and ''molecule'' is often used when referring to polyatomic ions. A molecule may be homonuclear, that is, it consists of atoms of one chemical element, e.g. two atoms in the oxygen molecule (O2); or it may be heteronuclear, a chemical compound composed of more than one element, e.g. water (two hydrogen atoms and one oxygen atom; H2O). In the kinetic theory of gases, the term ''molecule'' is often used for any gaseous particle regardless of its composition. This relaxes the requirement that a molecule contains two or more atoms, since the noble gases are individual atoms. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic bonds, are typically not consid ... [...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, and an ... [...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 class ha ... [...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] |
Bacillomycin
Bacillomycins are a group of antifungal polypeptide antibiotics isolated from ''Bacillus subtilis ''Bacillus subtilis'', known also as the hay bacillus or grass bacillus, is a Gram-positive, catalase-positive bacterium, found in soil and the gastrointestinal tract of ruminants, humans and marine sponges. As a member of the genus ''Bacillu ...''. Examples include: * Bacillomycin A (fungosin, structure unknown) * Bacillomycin C (structure unknown) * Bacillomycin D (C45H68N10O15) * Bacillomycin F (C52H84N12O14) * Bacillomycin Fc (C52H84N12O14) * Bacillomycin L (Landy substance) * Bacillomycin S (structure unknown) References Polypeptide antibiotics Antifungals {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipid
Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes. Lipids have applications in the cosmetic and food industries, and in nanotechnology. Lipids may be broadly defined as hydrophobic or amphiphilic small molecules; the amphiphilic nature of some lipids allows them to form structures such as vesicles, multilamellar/unilamellar liposomes, or membranes in an aqueous environment. Biological lipids originate entirely or in part from two distinct types of biochemical subunits or "building-blocks": ketoacyl and isoprene groups. Using this approach, lipids may be divided into eight categories: fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, and polyketides (derived from condensati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agonists
An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an Receptor antagonist, antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist. Etymology From the Ancient Greek language, Greek αγωνιστής (agōnistēs), contestant; champion; rival < αγων (agōn), contest, combat; exertion, struggle < αγω (agō), I lead, lead towards, conduct; drive Types of agonists Receptor (biochemistry), Receptors can be activated by either endogenous agonists (such as hormones and neurotransmitters) or exogenous agonists (such as medication, drugs), resulting in a biological response. A physiological agonism and ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
