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Parkeol
Parkeol is a relatively uncommon sterol secondary metabolite found mostly in plants, particularly noted in ''Butyrospermum parkii'' (now called ''Vitellaria paradoxa'', or the shea tree). It can be synthesized as a minor product by several oxidosqualene cyclase enzymes, and is the sole product of the enzyme parkeol synthase. Parkeol is the dominant sterol found in the planctomycete ''Gemmata obscuriglobus'', a rare example of a sterol-synthesizing prokaryote. The only other sterol identified in this organism is lanosterol, a key component of the sterol biosynthetic pathway in animals and fungi; this relatively limited sterol repertoire may resemble the early evolution of sterol synthesis, which is ubiquitous in eukaryote Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...s. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parkeol Synthase
Parkeol synthase () is an enzyme with systematic name ''(3S)-2,3-epoxy-2,3-dihydrosqualene mutase (cyclizing, parkeol-forming)''. This enzyme catalyses the following chemical reaction : (3S)-2,3-epoxy-2,3-dihydrosqualene \rightleftharpoons parkeol Parkeol is a relatively uncommon sterol secondary metabolite found mostly in plants, particularly noted in ''Butyrospermum parkii'' (now called ''Vitellaria paradoxa'', or the shea tree). It can be synthesized as a minor product by several oxidos ... The enzyme from rice ('' Oryza sativa'') produces only parkeol. References External links * {{Portal bar, Biology, border=no EC 5.4.99 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemmata Obscuriglobus
''Gemmata obscuriglobus'' is a species of Gram-negative, aerobic, heterotrophic bacteria of the phylum Planctomycetota. ''G. obscuriglobus'' occur in freshwater habitats and was first described in 1984, and is the only described species in its genus. ''G. obscuriglobus'' is exceptional for its unusual morphology and for the unusual features in its genome, often considered to represent large differences in internal organization compared with most prokaryotes Structure and Morphology Cell shape and appendages ''G. obscuriglobus'' is a large, roughly spherical bacterium with a cell diameter of 1–2 μm. It is motile and possesses multiple flagella per cell. Internal cell composition Dense, compact DNA and a deeply invaginated membrane are characteristics of the species. Membrane structure Among the most notable features of ''G. obscuriglobus'' is its highly complex and morphologically distinctive cell membrane system, including deep invaginations of its membrane that hist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterol
Sterol is an organic compound with formula , whose molecule is derived from that of gonane by replacement of a hydrogen atom in position 3 by a hydroxyl group. It is therefore an alcohol of gonane. More generally, any compounds that contain the gonane structure, additional functional groups, and/or modified ring systems derived from gonane are called steroids. Therefore, sterols are a subgroup of the steroids. They occur naturally in most eukaryotes, including plants, animals, and fungi, and can also be produced by some bacteria (however likely with different functions). The most familiar type of animal sterol is cholesterol, which is vital to cell membrane structure, and functions as a precursor to fat-soluble vitamins and steroid hormones. While technically alcohols, sterols are classified by biochemists as lipids (fats in the broader sense of the term). Types Sterols of plants are called ''phytosterols'' and sterols of animals are called ''zoosterols''. The most importa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Metabolite
Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the normal growth, development, or reproduction of the organism. Instead, they generally mediate ecological interactions, which may produce a selective advantage for the organism by increasing its survivability or fecundity. Specific secondary metabolites are often restricted to a narrow set of species within a phylogenetic group. Secondary metabolites often play an important role in plant defense against herbivory and other interspecies defenses. Humans use secondary metabolites as medicines, flavourings, pigments, and recreational drugs. The term secondary metabolite was first coined by Albrecht Kossel, a 1910 Nobel Prize laureate for medicine and physiology in 1910. 30 years later a Polish botanist Friedrich Czapek described secondary metabolit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Butyrospermum Parkii
''Vitellaria paradoxa'' (formerly ''Butyrospermum parkii''), commonly known as shea tree, shi tree (), or vitellaria, is a tree of the family Sapotaceae. It is the only species in the genus ''Vitellaria'',''Vitellaria paradoxa''. AgroForestry Tree Database. World Agroforestry Centre. and is indigenous to . The shea fruit consists of a thin, tart, nutritious pulp that surrounds a relatively large, oil-rich seed from which is extracted. It is a deciduous tree usually 7–15 m (23–49 ft.) tall, but has reached 25 m (82 ft.) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidosqualene Cyclase
Oxidosqualene cyclases (OSC) are enzymes involved in cyclization reactions of 2,3-oxidosqualene to form sterols or triterpenes. Introduction There are two major groups of sterol-producing OSC enzymes: * Cycloartenol synthase (CAS), found in all plants, which produces primarily cycloartenol * Lanosterol synthase (LAS), found in all animals and fungi, and occasionally in plants, which produces primarily lanosterol Sterols and triterpenes are extremely diverse classes of natural products, particularly in plants, which often contain numerous OSC enzymes with different substrate and product specificities; common examples include lupeol synthase and beta-amyrin synthase. OSC enzymes' catalytic mechanism is similar to the prokaryotic squalene-hopene cyclase. Directed evolution and protein design have been used to identify small numbers of point mutations that alter the product specificities of OSC enzymes, most notably in altering a cycloartenol synthase to produce predominantly lano ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planctomycete
The Planctomycetota are a phylum of widely distributed bacteria, occurring in both aquatic and terrestrial habitats. They play a considerable role in global carbon and nitrogen cycles, with many species of this phylum capable of anaerobic ammonium oxidation, also known as anammox. Many Planctomycetota occur in relatively high abundance as biofilms, often associating with other organisms such as macroalgae and marine sponges. Planctomycetota are included in the PVC superphylum along with Verrucomicrobiota, Chlamydiota, Lentisphaerota, Kiritimatiellaeota, and ''Candidatus'' ''Omnitrophica''. The phylum Planctomycetota is composed of the classes Planctomycetia and Phycisphaerae. First described in 1924, members of the Planctomycetota were identified as eukaryotes and were only later described as bacteria in 1972. Early examination of members of the Planctomycetota suggested a cell plan differing considerably from other bacteria, although they are now confirmed as Gram-negative bacter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prokaryote
A prokaryote () is a single-celled organism that lacks a nucleus and other membrane-bound organelles. The word ''prokaryote'' comes from the Greek πρό (, 'before') and κάρυον (, 'nut' or 'kernel').Campbell, N. "Biology:Concepts & Connections". Pearson Education. San Francisco: 2003. In the two-empire system arising from the work of Édouard Chatton, prokaryotes were classified within the empire Prokaryota. But in the three-domain system, based upon molecular analysis, prokaryotes are divided into two domains: ''Bacteria'' (formerly Eubacteria) and ''Archaea'' (formerly Archaebacteria). Organisms with nuclei are placed in a third domain, Eukaryota. In the study of the origins of life, prokaryotes are thought to have arisen before eukaryotes. Besides the absence of a nucleus, prokaryotes also lack mitochondria, or most of the other membrane-bound organelles that characterize the eukaryotic cell. It was once thought that prokaryotic cellular components within the cytop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lanosterol
Lanosterol is a tetracyclic triterpenoid and is the compound from which all animal and fungal steroids are derived. By contrast plant steroids are produced via cycloartenol. Role in biosynthesis of other steroids Elaboration of lanosterol under enzyme catalysis leads to the core structure of steroids. 14-Demethylation of lanosterol by CYP51 eventually yields cholesterol. Biosynthesis Research Lanosterol has been identified as a key component in maintaining eye lens clarity. Pre-clinical research has identified Lanosterol as a possible agent for the reversal and prevention of cataracts. In vivo experiments on dogs showed significant reversal of cataracts within 6 weeks of lanosterol injection. In 2018, Lanosterol was shown to improve lens clarity in cells with lens clouding due to aging or physical stressors. A subsequent study found positive results on the optics of the lens in mice with cataracts (Wang, Hoshino,Uesugi, Yagi, Pierscionek and Andley (2022). Use Lanosterol is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biosynthetic Pathway
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the conversion of food to building blocks for proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of metabolic wastes. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments. The word metabolism can also refer to the sum of all chemical reactions that occur in living organisms, including digestion and the transportation of substances into and between different cells, in which case the above described set of reactions within the cells is called intermediary (or intermediate) metabolism. Metabolic reactions may be categorized as ''catabolic'' – the ''breaking down'' of compounds (for example, of glucose to pyruvate by cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation tends to exist within any given population as a result of genetic mutation and recombination. Evolution occurs when evolutionary processes such as natural selection (including sexual selection) and genetic drift act on this variation, resulting in certain characteristics becoming more common or more rare within a population. The evolutionary pressures that determine whether a characteristic is common or rare within a population constantly change, resulting in a change in heritable characteristics arising over successive generations. It is this process of evolution that has given rise to biodiversity at every level of biological organisation, including the levels of species, individual organisms, and molecules. The theory of evolution by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
