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Brazzein
Brazzein is a sweet-tasting protein that occurs naturally in oubli (''Pentadiplandra brazzeana''), a fruit native to the Atlantic coastal areas of Central Africa. Brazzein was first isolated in 1994 by scientists at the University of Wisconsin–Madison. It is roughly 500 to 2000 times sweeter than sucrose. Brazzein is found in the extracellular region of oubli fruit, in the pulp tissue surrounding the seeds. After pentadin, discovered in 1989, brazzein is the second sweet-tasting protein discovered in the Oubli fruit. Like other sweet proteins discovered in plants, such as monellin and thaumatin, brazzein is extremely sweet compared to commonly used sweeteners. The fruit tastes sweet to humans, monkeys, and bonobos, but gorillas have mutations in their sweetness receptors so that they do not find brazzein sweet, and they are not known to eat the fruit. Traditional use The Oubli plant (from which the protein was isolated) grows in Gabon and Cameroon, where its fruit has been c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentadiplandra Brazzeana
''Pentadiplandra brazzeana'', also known as oubli, is an evergreen shrub or liana that is the only species assigned to the genus ''Pentadiplandra'', and has been placed in a family of its own called Pentadiplandraceae. It produces large red berries, sometimes mottled with grey. It is known from West-Central Tropical Africa, between northern Angola, eastern Nigeria and western Democratic Republic of Congo. The berry is sweet in taste due to the protein, brazzein, which is substantially sweeter than saccharose. Brazzein may be useful as a low-calorie sweetener, but is not yet allowed as a food additive in the United States and the European Union. Description ''Pentadiplandra brazzeana'' is a monoecious shrub of maximally , but can also develop into a liana, climbing up to high in the trees. The shrub morph usually has a mass of branched bulging roots, while the liana morph has a large, fleshy tuber. The branches are without hair and carry alternately set, simple and entire leav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentadin
Pentadin, a sweet-tasting protein, was discovered and isolated in 1989 from the fruit of oubli ('' Pentadiplandra brazzeana'' ), a climbing shrub growing in some tropical countries of Africa. '' Pentadiplandra brazzeana'' berry consists of a red pericarp with seeds and flesh containing sweet tasting proteins that can be extracted for production of a sugar substitute. History Pentadin (discovered in 1989) and brazzein (discovered in 1994) are the two names proposed for the sweet-tasting protein(s) isolated via two different methods from the same African fruit, '' Pentadiplandra brazzeana''. The corresponding author of both these publications has later opined that pentadin and brazzein are two different names for the same protein. Even though pentadin is the earlier proposed name, brazzein is the more commonly used name after more extensive characterisation of the sweet protein. Description Sweet tasting proteins have been known to exist for many years and indigenous people have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monellin
Monellin, a sweet protein, was discovered in 1969 in the fruit of the West African shrub known as serendipity berry ('' Dioscoreophyllum cumminsii''); it was first reported as a carbohydrate.GE Inglett, JF May. Serendipity berries - Source of a new intense sweetener. J Food Sci 1969, 34:408-411. The protein was named in 1972 after the Monell Chemical Senses Center in Philadelphia, U.S.A., where it was isolated and characterized. Protein composition Monellin's molecular weight is 10.7 kDa. It has two noncovalently associated polypeptide chains: an A chain sequence with 44 amino acid residues, and a B chain with 50 residues. Monellin chain A (44 AA): Monellin chain B (50 AA): Amino acid sequence of the sweet protein monellin adapted from Swiss-Prot biological database of protein. Monellin has a secondary structure consisting of five beta-strands that form an antiparallel beta-sheet and a 17-residue alpha-helix. In its natural form, monellin is composed of the two chains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Nuclear Magnetic Resonance Spectroscopy
Nuclear magnetic resonance spectroscopy of proteins (usually abbreviated protein NMR) is a field of structural biology in which NMR spectroscopy is used to obtain information about the structure and dynamics of proteins, and also nucleic acids, and their complexes. The field was pioneered by Richard R. Ernst and Kurt Wüthrich at the ETH, and by Ad Bax, Marius Clore, Angela Gronenborn at the NIH, and Gerhard Wagner at Harvard University, among others. Structure determination by NMR spectroscopy usually consists of several phases, each using a separate set of highly specialized techniques. The sample is prepared, measurements are made, interpretive approaches are applied, and a structure is calculated and validated. NMR involves the quantum-mechanical properties of the central core ("nucleus") of the atom. These properties depend on the local molecular environment, and their measurement provides a map of how the atoms are linked chemically, how close they are in space, and how ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide Synthesis
In organic chemistry, peptide synthesis is the production of peptides, compounds where multiple amino acids are linked via amide bonds, also known as peptide bonds. Peptides are chemically synthesized by the condensation reaction of the carboxyl group of one amino acid to the amine group, amino group of another. Protecting group strategies are usually necessary to prevent undesirable side reactions with the various amino acid side chains. Chemical peptide synthesis most commonly starts at the carboxyl end of the peptide (C-terminus), and proceeds toward the amino-terminus (N-terminus). Protein biosynthesis (long peptides) in living organisms occurs in the opposite direction. The chemical synthesis of peptides can be carried out using classical solution-phase techniques, although these have been replaced in most research and development settings by solid-phase methods (see below). Solution-phase synthesis retains its usefulness in large-scale production of peptides for industrial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taste Receptor
A taste receptor or tastant is a type of cellular receptor that facilitates the sensation of taste. When food or other substances enter the mouth, molecules interact with saliva and are bound to taste receptors in the oral cavity and other locations. Molecules which give a sensation of taste are considered "sapid". Vertebrate taste receptors are divided into two families: * Type 1, sweet, first characterized in 2001: – * Type 2, bitter, first characterized in 2000: In humans there are 25 known different bitter receptors, in cats there are 12, in chickens there are three, and in mice there are 35 known different bitter receptors. Visual, olfactive, "sapictive" (the perception of tastes), trigeminal (hot, cool), mechanical, all contribute to the perception of ''taste''. Of these, transient receptor potential cation channel subfamily V member 1 ( TRPV1) vanilloid receptors are responsible for the perception of heat from some molecules such as capsaicin, and a CMR1 receptor i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sugar Substitute
A sugar substitute or artificial sweetener, is a food additive that provides a sweetness like that of sugar while containing significantly less food energy than sugar-based sweeteners, making it a zero-calorie () or low-calorie sweetener. Artificial sweeteners may be derived through manufacturing of plant extracts or processed by chemical synthesis. Sugar substitute products are commercially available in various forms, such as small pills, powders and packets. Common sugar substitutes include aspartame, monk fruit extract, saccharin, sucralose, stevia, acesulfame potassium (ace-K) and cyclamate. These sweeteners are a fundamental ingredient in diet drinks to sweeten them without adding calories. Additionally, sugar alcohols such as erythritol, xylitol and sorbitol are derived from sugars. No links have been found between approved artificial sweeteners and cancer in humans. Reviews and dietetic professionals have concluded that moderate use of non-nutritive sweetener ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspartame
Aspartame is an artificial non-saccharide sweetener commonly used as a sugar substitute in foods and beverages. 200 times sweeter than sucrose, it is a methyl ester of the aspartic acid/phenylalanine dipeptide with brand names NutraSweet, Equal, and Canderel. Discovered in 1965, aspartame was approved by the US Food and Drug Administration (FDA) in 1974 and re-approved in 1981 after its initial approval was briefly revoked. Aspartame is one of the most studied food additives in the human food supply. Reviews by over 100 governmental regulatory bodies found the ingredient safe for consumption at the normal acceptable daily intake limit. Uses Aspartame is about 180 to 200 times sweeter than sucrose (table sugar). Due to this property, even though aspartame produces roughly the same energy per gram when metabolized as sucrose does, , the quantity of aspartame needed to produce the same sweetness is so small that its caloric contribution is negligible. The sweet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stevia
Stevia () is a sweet sugar substitute that is about 50 to 300 times sweetness, sweeter than sugar. It is extracted from the leaves of ''Stevia rebaudiana'', a plant native to areas of Paraguay and Brazil. The active compounds in stevia are steviol glycosides (mainly stevioside and rebaudioside). Stevia is heat-stable, pH-stable, and not fermentation (food), fermentable. Humans cannot metabolize the glycosides in stevia, and it therefore has zero calories. Its taste has a slower onset and longer duration than that of sugar, and at high concentrations some of its extracts may have an aftertaste described as licorice-like or Bitter taste, bitter. Stevia is used in sugar-reduced and calorie-reduced food and beverage products as an alternative for variants with sugar. The legal status of stevia as a food additive or dietary supplement varies from country to country. In the United States, certain high-purity ''stevia glycoside'' extracts have been generally recognized as safe (GRA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curculin
Curculin or neoculin is a sweet protein complex that was discovered and isolated in 1990 from the fruit of '' Curculigo latifolia'' ( Hypoxidaceae). Like miraculin, curculin exhibits taste-modifying activity; however, unlike miraculin, it also exhibits a sweet taste by itself. After consumption of curculin, water and sour solutions taste sweet. mRNAs for a related protein complex is found in '' Curculigo capitulata'' fruits, though at a much lower level of expression – so low that the product is undetectable by immunoblotting. Protein structure The active form of curculin is a heterodimer consisting of two monomeric units connected through two disulfide bridges. The mature monomers each consist of a sequence of 114 amino acids, weighing 12.5 kDa (curculin 1) and 12.7 kDa (curculin 2), respectively. While each of the two isoforms is capable of forming a homodimer, these do not possess the sweet taste nor the taste-modifying activity of the heterodimeric form. To avoid c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escherichia Coli
''Escherichia coli'' ( )Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Escherichia'' that is commonly found in the lower intestine of warm-blooded organisms. Most ''E. coli'' strains are part of the normal microbiota of the gut, where they constitute about 0.1%, along with other facultative anaerobes. These bacteria are mostly harmless or even beneficial to humans. For example, some strains of ''E. coli'' benefit their hosts by producing vitamin K2 or by preventing the colonization of the intestine by harmful pathogenic bacteria. These mutually beneficial relationships between ''E. coli'' and humans are a type of mutualistic biological relationship—where both the humans and the ''E. coli'' are benefitting each other. ''E. coli'' is expelled into the environment within fecal matter. The bacterium grows massi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
