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Gelonin
Gelonin is a type 1 ribosome-inactivating protein and toxin of approximately 30 kDa found in the seeds of the Himalayan plant Gelonium multiflorum. In cell-free systems gelonin exerts powerful N-glycosidase activity on the 28S rRNA unit of eukaryotic ribosomes by cleaving out adenine at the 4324 site. Gelonin lacks carbohydrate-binding domains so it is unable to cross the plasma membrane, making it highly effective only in cell free systems. Structure Gelonin is a 30 kDa protein. Gelonin is a dimer, consisting of two identical monomers. Each monomer is composed of 251 amino acids, for a total of 502 residues. Gelonin is classified as an (α + β) protein, as its secondary structure consists of both beta sheets and alpha helices. Each monomer’s first 100 amino acids form 10 beta sheets, while their last 151 amino acids form 10 alpha helices. Gelonin’s two dimers are stabilized by hydrophobic interactions and hydrogen bonds. Specifically, the Asn22, Arg178, Asn180, and Lys2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gelonin Full Structure
Gelonin is a type 1 ribosome-inactivating protein and toxin of approximately 30 kDa found in the seeds of the Himalayan plant Gelonium multiflorum. In cell-free systems gelonin exerts powerful N-glycosidase activity on the 28S rRNA unit of eukaryotic ribosomes by cleaving out adenine at the 4324 site. Gelonin lacks carbohydrate-binding domains so it is unable to cross the plasma membrane, making it highly effective only in cell free systems. Structure Gelonin is a 30 kDa protein. Gelonin is a dimer, consisting of two identical monomers. Each monomer is composed of 251 amino acids, for a total of 502 residues. Gelonin is classified as an (α + β) protein, as its secondary structure consists of both beta sheets and alpha helices. Each monomer’s first 100 amino acids form 10 beta sheets, while their last 151 amino acids form 10 alpha helices. Gelonin’s two dimers are stabilized by hydrophobic interactions and hydrogen bonds. Specifically, the Asn22, Arg178, Asn180, and Lys23 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saporin
Saporin is a protein that is useful in biological research applications, especially studies of behavior. Saporins are so-called ribosome inactivating proteins (RIPs), due to its N-glycosidase activity, from the seeds of ''Saponaria officinalis'' (common name: soapwort). It was first described by Fiorenzo Stirpe and his colleagues in 1983 in an article that illustrated the unusual stability of the protein. Among the RIPs are some of the most toxic molecules known, such as ricin and abrin. Each of these toxins contain a second protein subunit, which inserts the RIP into a cell, enabling it to enzymatically inactivate the ribosomes, shutting down protein synthesis, stopping basic cell functions, resulting in cell death, and eventually causing death of the victim. Saporin has no chain capable of inserting it into the cell. Thus it and the soapwort plant are safe to handle. This has aided its use in research. If given a method of entry into the cell, saporin becomes a very potent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Helices
The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located four residues earlier along the protein sequence. The alpha helix is also called a classic Pauling–Corey–Branson α-helix. The name 3.613-helix is also used for this type of helix, denoting the average number of residues per helical turn, with 13 atoms being involved in the ring formed by the hydrogen bond. Among types of local structure in proteins, the α-helix is the most extreme and the most predictable from sequence, as well as the most prevalent. Discovery In the early 1930s, William Astbury showed that there were drastic changes in the X-ray fiber diffraction of moist wool or hair fibers upon significant stretching. The data suggested that the unstretched fibers had a coiled molecular structure with a characteristic repeat of ≈. Astbu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bispecific Antibodies
A bispecific monoclonal antibody (BsMAb, BsAb) is an artificial protein that can simultaneously bind to two different types of antigen or two different epitopes on the same antigen. Naturally occurring antibodies typically only target one antigen. BsAbs can be manufactured in several structural formats. BsAbs can be designed to recruit and activate immune cells, to interfere with receptor signaling and inactivate signaling ligands, and to force association of protein complexes. BsAbs have been explored for cancer immunotherapy, drug delivery, and Alzeimer's disease. Development history The original concept of BsAbs was proposed by Nisonoff and his collaborators in the 1960s, including the first idea of antibody architecture and other findings. In 1975, the problem of producing pure antibodies was solved by the creation of hybridoma technology, and the new era of monoclonal antibodies (MoAbs) came. In 1983, Milstein and Cuello created hybrid-hybridoma (quadroma) technology. In 1988 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Listeriolysin O
Listeriolysin O (LLO) is a hemolysin produced by the bacterium '' Listeria monocytogenes'', the pathogen responsible for causing listeriosis. The toxin may be considered a virulence factor, since it is crucial for the virulence of ''L. monocytogenes''. Biochemistry Listeriolysin O is a non-enzymatic, cytolytic, thiol-activated, cholesterol-dependent cytolysin; hence, it is activated by reducing agents and inhibited by oxidizing agents. However, LLO differs from other thiol-activated toxins, since its cytolytic activity is maximized at a pH of 5.5. By maximizing activity at a pH of 5.5, LLO is selectively activated within the acidic phagosomes (average pH ~ 5.9) of cells that have phagocytosed ''L. monocytogenes''. After LLO lyses the phagosome, the bacterium escapes into the cytosol, where it can grow intracellularly. Upon release from the phagosome, the toxin has little activity in the more basic cytosol. Furthermore, LLO permits ''L. monocytogenes'' to escape from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liposome
A liposome is a small artificial vesicle, spherical in shape, having at least one lipid bilayer. Due to their hydrophobicity and/or hydrophilicity, biocompatibility, particle size and many other properties, liposomes can be used as drug delivery vehicles for administration of pharmaceutical drugs and nutrients, such as lipid nanoparticles in mRNA vaccines, and DNA vaccines. Liposomes can be prepared by disrupting biological membranes (such as by sonication). Liposomes are most often composed of phospholipids, especially phosphatidylcholine and cholesterol, but may also include other lipids, such as egg, phosphatidylethanolamine, as long as they are compatible with lipid bilayer structure. A liposome design may employ surface ligands for attaching to unhealthy tissue. The major types of liposomes are the multilamellar vesicle (MLV, with several lamellar phase lipid bilayers), the small unilamellar liposome vesicle (SUV, with one lipid bilayer), the large unilamellar vesicle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell-penetrating Peptide
Cell-penetrating peptides (CPPs) are short peptides that facilitate cellular intake and uptake of molecules ranging from nanosize particles to small chemical compounds to large fragments of DNA. The "cargo" is associated with the peptides either through chemical linkage via covalent bonds or through non-covalent interactions. CPPs deliver the cargo into cells, commonly through endocytosis, for use in research and medicine. Current use is limited by a lack of cell specificity in CPP-mediated cargo delivery and insufficient understanding of the modes of their uptake. Other delivery mechanisms that have been developed include CellSqueeze and electroporation. CPPs typically have an amino acid composition that either contains a high relative abundance of positively charged amino acids such as lysine or arginine or has sequences that contain an alternating pattern of polar, charged amino acids and non-polar, hydrophobic amino acids. These two types of structures are referred to as poly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxocarbenium
An oxocarbenium ion (or oxacarbenium ion) is a chemical species characterized by a central sp2-hybridized carbon, an oxygen substituent, and an overall positive charge that is delocalized between the central carbon and oxygen atoms. An oxocarbenium ion is represented by two limiting resonance structures, one in the form of a carbenium ion with the positive charge on carbon and the other in the form of an oxonium species with the formal charge on oxygen. As a resonance hybrid, the true structure falls between the two. Compared to neutral carbonyl compounds like ketones or esters, the carbenium ion form is a larger contributor to the structure. They are common reactive intermediates in the hydrolysis of glycosidic bonds, and are a commonly used strategy for chemical glycosylation. These ions have since been proposed as reactive intermediates in a wide range of chemical transformations, and have been utilized in the total synthesis of several natural products. In addition, they c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
28S RRNA
Crazy Eights is a shedding-type card game for two to seven players and the best known American member of the Eights Group which also includes Pig and Spoons. The object of the game is to be the first player to discard all of their cards. The game is similar to Switch and Mau Mau. Originally this was played primarily by children with the left over cards not used in Euchre. Now a standard 52-card deck is used when there are five or fewer players. When there are more than five players, two decks are shuffled together and all 104 cards are used. Origins The game first appeared as ''Eights'' in the 1930s, and the name ''Crazy Eights'' dates to the 1940s, derived from the United States military designation for discharge of mentally unstable soldiers, Section 8. It may have derived from the German game of Mau-Mau. There are many variations of the basic game, under names including ''Craits'', '' Last Card'', ''Switch'', and ''Black Jack''. Bartok, Mao, Taki, and Uno add further e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Site
In biology and biochemistry, the active site is the region of an enzyme where substrate molecules bind and undergo a chemical reaction. The active site consists of amino acid residues that form temporary bonds with the substrate ( binding site) and residues that catalyse a reaction of that substrate (catalytic site). Although the active site occupies only ~10–20% of the volume of an enzyme, it is the most important part as it directly catalyzes the chemical reaction. It usually consists of three to four amino acids, while other amino acids within the protein are required to maintain the tertiary structure of the enzymes. Each active site is evolved to be optimised to bind a particular substrate and catalyse a particular reaction, resulting in high specificity. This specificity is determined by the arrangement of amino acids within the active site and the structure of the substrates. Sometimes enzymes also need to bind with some cofactors to fulfil their function. The a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Site Of Gelonin With Adenine
Active may refer to: Music * ''Active'' (album), a 1992 album by Casiopea * Active Records, a record label Ships * ''Active'' (ship), several commercial ships by that name * HMS ''Active'', the name of various ships of the British Royal Navy * USCS ''Active'', a US Coast Survey ship in commission from 1852 to 1861 * USCGC ''Active'', the name of various ships of the US Coast Guard * USRC ''Active'', the name of various ships of the US Revenue Cutter Service * USS ''Active'', the name of various ships of the US Navy Computers and electronics * Active Enterprises, a defunct video game developer * Sky Active, the brand name for interactive features on Sky Digital available in the UK and Ireland * Active (software), software used for open publishing by Indymedia; see Independent Media Center Sciences * Thermodynamic activity, measure of an effective concentration of a species in a mixture. * Activation, in chemistry the process whereby something is prepared for a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Bond
In chemistry, a hydrogen bond (or H-bond) is a primarily electrostatic force of attraction between a hydrogen (H) atom which is covalently bound to a more electronegative "donor" atom or group (Dn), and another electronegative atom bearing a lone pair of electrons—the hydrogen bond acceptor (Ac). Such an interacting system is generally denoted , where the solid line denotes a polar covalent bond, and the dotted or dashed line indicates the hydrogen bond. The most frequent donor and acceptor atoms are the second-row elements nitrogen (N), oxygen (O), and fluorine (F). Hydrogen bonds can be intermolecular (occurring between separate molecules) or intramolecular (occurring among parts of the same molecule). The energy of a hydrogen bond depends on the geometry, the environment, and the nature of the specific donor and acceptor atoms and can vary between 1 and 40 kcal/mol. This makes them somewhat stronger than a van der Waals interaction, and weaker than fully cova ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
