adenosinetriphosphatase

アデノシン三リン酸分解酵素、ATPアーゼ

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adenosine triphosphatase、ATPase

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/02/23 11:57:36」(JST)

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Adenosine triphosphate

Adenosine diphosphate

ATPases are a class of enzymes that catalyze the decomposition of adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and a free phosphate ion. This dephosphorylation reaction releases energy, which the enzyme (in most cases) harnesses to drive other chemical reactions that would not otherwise occur. This process is widely used in all known forms of life.

Some such enzymes are integral membrane proteins (anchored within biological membranes), and move solutes across the membrane, typically against their concentration gradient. These are called transmembrane ATPases.

Functions

Na⁺/K⁺ATPase

Transmembrane ATPases import many of the metabolites necessary for cell metabolism and export toxins, wastes, and solutes that can hinder cellular processes. An important example is the sodium-potassium exchanger (or Na⁺/K⁺ATPase), which establishes the ionic concentration balance that maintains the cell potential. Another example is the hydrogen potassium ATPase (H⁺/K⁺ATPase or gastric proton pump) that acidifies the contents of the stomach.

Besides exchangers, other categories of transmembrane ATPase include co-transporters and pumps (however, some exchangers are also pumps). Some of these, like the Na⁺/K⁺ATPase, cause a net flow of charge, but others do not. These are called "electrogenic" and "nonelectrogenic" transporters, respectively.

Mechanism

The coupling between ATP hydrolysis and transport is more or less a strict chemical reaction, in which a fixed number of solute molecules are transported for each ATP molecule that is hydrolyzed; for example, 3 Na⁺ ions out of the cell and 2 K⁺ ions inward per ATP hydrolyzed, for the Na⁺/K⁺ exchanger.

Transmembrane ATPases harness the chemical potential energy of ATP, because they perform mechanical work: they transport solutes in a direction opposite to their thermodynamically preferred direction of movement—that is, from the side of the membrane where they are in low concentration to the side where they are in high concentration. This process is considered active transport.

For example, the blocking of the vesicular H⁺-ATPAses would increase the pH inside vesicles and decrease the pH of the cytoplasm.

Transmembrane ATP synthases

Main article: ATP synthase

The ATP synthase of mitochondria and chloroplasts is an anabolic enzyme that harnesses the energy of a transmembrane proton gradient as an energy source for adding an inorganic phosphate group to a molecule of adenosine diphosphate (ADP) to form a molecule of adenosine triphosphate (ATP).

This enzyme works when a proton moves down the concentration gradient, giving the enzyme a spinning motion. This unique spinning motion bonds ADP and P together to create ATP.

ATP synthase can also function in reverse, that is, use energy released by ATP hydrolysis to pump protons against their thermodynamic gradient.

Classification

There are different types of ATPases, which can differ in function (ATP synthesis and/or hydrolysis), structure (F-, V- and A-ATPases contain rotary motors) and in the type of ions they transport.

• F-ATPases (F1FO-ATPases) in mitochondria, chloroplasts and bacterial plasma membranes are the prime producers of ATP, using the proton gradient generated by oxidative phosphorylation (mitochondria) or photosynthesis (chloroplasts).
• V-ATPases (V1VO-ATPases) are primarily found in eukaryotic vacuoles, catalysing ATP hydrolysis to transport solutes and lower pH in organelles like proton pump of lysosome.
• A-ATPases (A1AO-ATPases) are found in Archaea and function like F-ATPases
• P-ATPases (E1E2-ATPases) are found in bacteria, fungi and in eukaryotic plasma membranes and organelles, and function to transport a variety of different ions across membranes.
• E-ATPases are cell-surface enzymes that hydrolyse a range of NTPs, including extracellular ATP.

P-ATPase

Main article: P-ATPase

P-ATPases (sometime known as E1-E2 ATPases) are found in bacteria and in a number of eukaryotic plasma membranes and organelles. Its name is due to short time attachment of inorganic phosphate at the aspartate residues at the time of activation.P-ATPases function to transport a variety of different compounds, including ions and phospholipids, across a membrane using ATP hydrolysis for energy. There are many different classes of P-ATPases, each of which transports a specific type of ion: H⁺, Na⁺, K⁺, Mg²⁺, Ca²⁺, Ag⁺ and Ag²⁺, Zn²⁺, Co²⁺, Pb²⁺, Ni²⁺, Cd²⁺, Cu⁺ and Cu²⁺. P-ATPases can be composed of one or two polypeptides, and can usually assume two main conformations called E1 and E2.

Human genes

(See Human ATPase)

• Na⁺/K⁺ transporting: ATP1A1, ATP1A2, ATP1A3, ATP1A4, ATP1B1, ATP1B2, ATP1B3, ATP1B4
• Ca⁺⁺ transporting: ATP2A1, ATP2A2, ATP2A3, ATP2B1, ATP2B2, ATP2B3, ATP2B4, ATP2C1
• Mg⁺⁺ transporting: ATP3
• H⁺/K⁺ exchanging: ATP4A, ATP4B
• H⁺ transporting, mitochondrial: ATP5A1, ATP5B, ATP5C1, ATP5C2, ATP5D, ATP5E, ATP5F1, ATP5G1, ATP5G2, ATP5G3, ATP5H, ATP5I, ATP5J, ATP5J2, ATP5L, ATP5L2, ATP5O, ATP5S
• H⁺ transporting, lysosomal: ATP6AP1, ATP6AP2, ATP6V1A, ATP6V1B1, ATP6V1B2, ATP6V1C1, ATP6V1C2, ATP6V1D, ATP6V1E1, ATP6V1E2, ATP6V1F, ATP6V1G1, ATP6V1G2, ATP6V1G3, ATP6V1H, ATP6V0A1, ATP6V0A2, ATP6V0A4, ATP6V0B, ATP6V0C, ATP6V0D1, ATP6V0D2, ATP6V0E
• Cu⁺⁺ transporting: ATP7A, ATP7B
• Class I, type 8: ATP8A1, ATP8B1, ATP8B2, ATP8B3, ATP8B4
• Class II, type 9: ATP9A, ATP9B
• Class V, type 10: ATP10A, ATP10B, ATP10D
• Class VI, type 11: ATP11A, ATP11B, ATP11C
• H⁺/K⁺ transporting, nongastric: ATP12A
• type 13: ATP13A1, ATP13A2, ATP13A3, ATP13A4, ATP13A5

See also

• ATP synthase
• ATP synthase alpha/beta subunits
• AAA proteins
• P-ATPase

External links

• "ATP synthase - a splendid molecular machine"
• ATPase at the US National Library of Medicine Medical Subject Headings (MeSH)
• UMich Orientation of Proteins in Membranes families/superfamily-5 - Proton or sodium translocating F- and V-type ATPases
• UMich Orientation of Proteins in Membranes families/superfamily-22 - Different conformations of P-type ATPase
• Electron microscopy structures of ATPases from the EM Data Bank(EMDB)

English Journal

• Melanocytes--a novel tool to study mitochondrial dysfunction in Duchenne muscular dystrophy.

• Pellegrini C, Zulian A, Gualandi F, Manzati E, Merlini L, Michelini ME, Benassi L, Marmiroli S, Ferlini A, Sabatelli P, Bernardi P, Maraldi NM.SourceDepartment of Medical Science, University of Ferrara, Ferrara, Italy.
• Journal of cellular physiology.J Cell Physiol.2013 Jun;228(6):1323-31. doi: 10.1002/jcp.24290.
• Dystrophin is a subsarcolemmal protein that, by linking the actin cytoskeleton to the extracellular matrix via dystroglycans, is critical for the integrity of muscle fibers. Here, we report that epidermal melanocytes, obtained from conventional skin biopsy, express dystrophin with a restricted local
• PMID 23169061

• Chronic exposure to stress hormones alters the subtype of store-operated channels expressed in H19-7 hippocampal neuronal cells.

• Piron M, Villereal ML.SourceDepartment of Neurobiology, Pharmacology and Physiology, University of Chicago, Chicago, IL 60637, USA.
• Journal of cellular physiology.J Cell Physiol.2013 Jun;228(6):1332-43. doi: 10.1002/jcp.24289.
• Differentiating H19-7 hippocampal precursor cells up-regulate (∼4.3-fold) store-operated channel (SOC) activity; relatively linear current-voltage curves indicate an I(SOC) subtype of SOC. In differentiated H19-7 neurons, the majority of agonist (arginine vasopressin, AVP)-stimulated Ca(2+) entry
• PMID 23169006

• Known glioma risk loci are associated with glioma with a family history of brain tumours -- a case-control gene association study.

• Melin B, Dahlin AM, Andersson U, Wang Z, Henriksson R, Hallmans G, Bondy ML, Johansen C, Feychting M, Ahlbom A, Kitahara CM, Wang SS, Ruder AM, Carreón T, Butler MA, Inskip PD, Purdue M, Hsing AW, Mechanic L, Gillanders E, Yeager M, Linet M, Chanock SJ, Hartge P, Rajaraman P.SourceDepartment of Radiation Sciences, Oncology, Umeå University, Umeå, Sweden. beatrice.melin@onkologi.umu.se
• International journal of cancer. Journal international du cancer.Int J Cancer.2013 May 15;132(10):2464-8. doi: 10.1002/ijc.27922. Epub 2012 Nov 21.
• Familial cancer can be used to leverage genetic association studies. Recent genome-wide association studies have reported independent associations between seven single nucleotide polymorphisms (SNPs) and risk of glioma. The aim of this study was to investigate whether glioma cases with a positive fa
• PMID 23115063

Japanese Journal

• Acylated Kaempferol Glycosides from Laurus nobilis Leaves and Their Inhibitory Effects on Na⁺/K⁺-Adenosine Triphosphatase

• Biological and Pharmaceutical Bulletin 35(3), 428-432, 2012
• NAID 130001872327

• High Level of Skeletal Muscle Carnosine Contributes to the Latter Half of Exercise Performance during 30-s Maximal Cycle Ergometer Sprinting

• The Japanese journal of physiology 52(2), 199-205, 2002-04-01
• NAID 10009505709

• Characteristics of Adenosinetriphosphatase and Inorganic Pyrophosphatase in Tonoplasts Isolated from Three CAM Species, Ananas comosus, Kalanchoe pinnata and K. daigremontiana

• Plant production science 3(1), 24-31, 2000-03-01
• NAID 110001720652

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★リンクテーブル★

リンク元	「アデノシン三リン酸分解酵素」

「アデノシン三リン酸分解酵素」

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英

adenosinetriphosphatase、ATPase

関

ATP分解酵素、ATPアーゼ、ATP加水分解酵素