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Sirtuin
Sirtuins are a family of signaling proteins involved in metabolic regulation. They are ancient in animal evolution and appear to possess a highly conserved structure throughout all kingdoms of life. Chemically, sirtuins are a class of proteins that possess either mono- ADP-ribosyltransferase or deacylase activity, including deacetylase, desuccinylase, demalonylase, demyristoylase and depalmitoylase activity. The name Sir2 comes from the yeast gene 'silent mating-type information regulation 2', the gene responsible for cellular regulation in yeast. From ''in vitro'' studies, sirtuins are implicated in influencing cellular processes like aging, transcription, apoptosis, inflammation and stress resistance, as well as energy efficiency and alertness during low-calorie situations. As of 2018, there was no clinical evidence that sirtuins affect human aging. Yeast Sir2 and some, but not all, sirtuins are protein deacetylases. Unlike other known protein deacetylases, which simply hyd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sir2
Sirtuin 1, also known as nicotinamide adenine dinucleotide, NAD-dependent deacetylase sirtuin-1, is a protein that in humans is encoded by the SIRT1 gene. SIRT1 stands for sirtuin (silent mating type information regulation 2 homolog) 1 (''Saccharomyces cerevisiae, S. cerevisiae''), referring to the fact that its sirtuin homolog (biological equivalent across species) in yeast ''(Saccharomyces cerevisiae)'' is Sir2. SIRT1 is an enzyme located primarily in the cell nucleus that deacetylates transcription factors that contribute to cellular regulation (reaction to stressors, longevity). Function Sirtuin 1 is a member of the sirtuin family of proteins, Homology (biology)#Homology of sequences in genetics, homologs of the Sir2 gene in ''S. cerevisiae''. Members of the sirtuin family are characterized by a sirtuin core domain and grouped into four classes. The functions of human sirtuins have not yet been determined; however, yeast sirtuin proteins are known to regulate Epigenetics, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinamide Adenine Dinucleotide
Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an adenine nucleobase and the other nicotinamide. NAD exists in two forms: an oxidized and reduced form, abbreviated as NAD and NADH (H for hydrogen), respectively. In metabolism, nicotinamide adenine dinucleotide is involved in redox reactions, carrying electrons from one reaction to another. The cofactor is, therefore, found in two forms in cells: NAD is an oxidizing agent – it accepts electrons from other molecules and becomes reduced. This reaction, also with H+, forms NADH, which can then be used as a reducing agent to donate electrons. These electron transfer reactions are the main function of NAD. However, it is also used in other cellular processes, most notably as a substrate of enzymes in adding or removing chemical groups to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histone Deacetylase
Histone deacetylases (, HDAC) are a class of enzymes that remove acetyl groups (O=C-CH3) from an ε-N-acetyl lysine amino acid on a histone, allowing the histones to wrap the DNA more tightly. This is important because DNA is wrapped around histones, and DNA expression is regulated by acetylation and de-acetylation. Its action is opposite to that of histone acetyltransferase. HDAC proteins are now also called lysine deacetylases (KDAC), to describe their function rather than their target, which also includes non-histone proteins. HDAC super family Together with the acetylpolyamine amidohydrolases and the acetoin utilization proteins, the histone deacetylases form an ancient protein superfamily known as the histone deacetylase superfamily. Classes of HDACs in higher eukaryotes HDACs, are classified in four classes depending on sequence homology to the yeast original enzymes and domain organization: HDAC (except class III) contain zinc and are known as Zn2+-dependent hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calorie Restriction
Calorie restriction (caloric restriction or energy restriction) is a dietary regimen that reduces intake of energy from caloric foods & beverages without incurring malnutrition. "Reduce" can be defined relative to the subject's previous intake before intentionally restricting food or beverage consumption, or relative to an average person of similar body type. Calorie restriction is typically adopted intentionally to reduce body weight. It is recommended as a possible regimen by US dietary guidelines and scientific societies for body weight control. Health effects Recommendations Caloric intake control, and reduction for overweight individuals, is recommended by US dietary guidelines and science-based societies. Calorie restriction is recommended for people with diabetes and prediabetes, in combination with physical exercise and a weight loss goal of 5-15% for diabetes and 7-10% for prediabetes to prevent progression to diabetes. and mild calorie restriction may be benefici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ADP-ribosylation
ADP-ribosylation is the addition of one or more ADP-ribose moieties to a protein. It is a reversible post-translational modification that is involved in many cellular processes, including cell signaling, DNA repair, gene regulation and apoptosis. Improper ADP-ribosylation has been implicated in some forms of cancer. It is also the basis for the toxicity of bacterial compounds such as cholera toxin, diphtheria toxin, and others. History The first suggestion of ADP-ribosylation surfaced during the early 1960s. At this time, Pierre Chambon and coworkers observed the incorporation of ATP into hen liver nuclei extract. After extensive studies on the acid insoluble fraction, several different research laboratories were able to identify ADP-ribose, derived from NAD+, as the incorporated group. Several years later, the enzymes responsible for this incorporation were identified and given the name poly(ADP-ribose)polymerase. Originally, this group was thought to be a linear sequence of AD ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair. The five cardinal signs are heat, pain, redness, swelling, and Functio laesa, loss of function (Latin ''calor'', ''dolor'', ''rubor'', ''tumor'', and ''functio laesa''). Inflammation is a generic response, and therefore it is considered as a mechanism of innate immune system, innate immunity, as compared to adaptive immune system, adaptive immunity, which is specific for each pathogen. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aging
Ageing ( BE) or aging ( AE) is the process of becoming older. The term refers mainly to humans, many other animals, and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal. In a broader sense, ageing can refer to single cells within an organism which have ceased dividing, or to the population of a species. In humans, ageing represents the accumulation of changes in a human being over time and can encompass physical, psychological, and social changes. Reaction time, for example, may slow with age, while memories and general knowledge typically increase. Ageing increases the risk of human diseases such as cancer, Alzheimer's disease, diabetes, cardiovascular disease, stroke and many more. Of the roughly 150,000 people who die each day across the globe, about two-thirds die from age-related causes. Current ageing theories are assigned to the damage concept, whereby the accumulation of damage (such as DNA ox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Deacetylase
A protein deacetylase is any enzyme that removes acetyl groups from lysine amino acids in proteins. The main ones are histone deacetylases (HDACs) and sirtuins (SIRT1,2,3,5). Because histone proteins were the first known substrate for protein deacetylases, the latter all tend to be called HDACs of one class or another. Human protein deacetylase enzymes have been categorized into * Class I (HDAC1,2,3,8); * Class II (HDAC4,5,6,7,9,10), * Class III (SIRT1,2,3,5,6), * Class IV (HDAC11 and its related enzymes). Class III are the NAD+ Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an aden ...-dependent protein deacetylases. References {{reflist Enzymes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinamide
Niacinamide or Nicotinamide (NAM) is a form of vitamin B3 found in food and used as a dietary supplement and medication. As a supplement, it is used by mouth to prevent and treat pellagra (niacin deficiency). While nicotinic acid (niacin) may be used for this purpose, niacinamide has the benefit of not causing skin flushing. As a cream, it is used to treat acne. It is a water-soluble vitamin. Niacinamide is the supplement name while Nicotinamide (NAM) is the scientific name. Side effects are minimal. At high doses liver problems may occur. Normal amounts are safe for use during pregnancy. Niacinamide is in the vitamin B family of medications, specifically the vitamin B3 complex. It is an amide of nicotinic acid. Foods that contain niacinamide include yeast, meat, milk, and green vegetables. Niacinamide was discovered between 1935 and 1937. It is on the World Health Organization's List of Essential Medicines. Niacinamide is available as a generic medication and over the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme Inhibitor
An enzyme inhibitor is a molecule that binds to an enzyme and blocks its activity. Enzymes are proteins that speed up chemical reactions necessary for life, in which substrate molecules are converted into products. An enzyme facilitates a specific chemical reaction by binding the substrate to its active site, a specialized area on the enzyme that accelerates the most difficult step of the reaction. An enzyme inhibitor stops ("inhibits") this process, either by binding to the enzyme's active site (thus preventing the substrate itself from binding) or by binding to another site on the enzyme such that the enzyme's catalysis of the reaction is blocked. Enzyme inhibitors may bind reversibly or irreversibly. Irreversible inhibitors form a chemical bond with the enzyme such that the enzyme is inhibited until the chemical bond is broken. By contrast, reversible inhibitors bind non-covalently and may spontaneously leave the enzyme, allowing the enzyme to resume its function. Reve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinamide
Niacinamide or Nicotinamide (NAM) is a form of vitamin B3 found in food and used as a dietary supplement and medication. As a supplement, it is used by mouth to prevent and treat pellagra (niacin deficiency). While nicotinic acid (niacin) may be used for this purpose, niacinamide has the benefit of not causing skin flushing. As a cream, it is used to treat acne. It is a water-soluble vitamin. Niacinamide is the supplement name while Nicotinamide (NAM) is the scientific name. Side effects are minimal. At high doses liver problems may occur. Normal amounts are safe for use during pregnancy. Niacinamide is in the vitamin B family of medications, specifically the vitamin B3 complex. It is an amide of nicotinic acid. Foods that contain niacinamide include yeast, meat, milk, and green vegetables. Niacinamide was discovered between 1935 and 1937. It is on the World Health Organization's List of Essential Medicines. Niacinamide is available as a generic medication and over the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribose
Ribose is a simple sugar and carbohydrate with molecular formula C5H10O5 and the linear-form composition H−(C=O)−(CHOH)4−H. The naturally-occurring form, , is a component of the ribonucleotides from which RNA is built, and so this compound is necessary for coding, decoding, regulation and expression of genes. It has a structural analog, deoxyribose, which is a similarly essential component of DNA. is an unnatural sugar that was first prepared by Emil Fischer and Oscar Piloty in 1891. It was not until 1909 that Phoebus Levene and Walter Jacobs recognised that was a natural product, the enantiomer of Fischer and Piloty's product, and an essential component of nucleic acids. Fischer chose the name "ribose" as it is a partial rearrangement of the name of another sugar, arabinose, of which ribose is an epimer at the 2' carbon; both names also relate to gum arabic, from which arabinose was first isolated and from which they prepared . Like most sugars, ribose exists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
