必須アミノ酸

WordNet

being or relating to or containing the essence of a plant etc; "essential oil"
absolutely necessary; vitally necessary; "essential tools and materials"; "funds essential to the completion of the project"; "an indispensable worker" (同)indispensable
basic and fundamental; "the essential feature"
street name for lysergic acid diethylamide (同)back breaker, battery-acid, dose, dot, Elvis, loony toons, Lucy in the sky with diamonds, pane, superman, window pane, Zen
any of various water-soluble compounds having a sour taste and capable of turning litmus red and reacting with a base to form a salt
having the characteristics of an acid; "an acid reaction"
pertaining to or containing any of a group of organic compounds of nitrogen derived from ammonia (同)aminic
the radical -NH2 (同)amino_group

PrepTutorEJDIC

『絶対必要な』,欠くことのできない / 『本質の』,本質的な / (植物・薬剤などの)エキスの,精の / (…に)不可欠の要素;(…の)主眼点,要点《+『of』+『名』》
酸性の / 酸味のある,すっぱい(sour) / (言葉・態度などが)厳しい,しんらつな / 酸 / すっぱいもの / 《俗》=LSD

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/08/23 08:28:16」(JST)

wiki en

An essential amino acid or indispensable amino acid is an amino acid that cannot be synthesized de novo by the organism (usually referring to humans), and therefore must be supplied in the diet.

Essentiality vs. conditional essentiality in humans

Essential	Nonessential **
Histidine	Alanine
Isoleucine	Arginine*
Leucine	Aspartate
Lysine	Cysteine*
Methionine	Glutamate
Phenylalanine	Glutamine*
Threonine	Glycine*
Tryptophan	Proline*
Valine	Serine*
	Tyrosine*
	Asparagine*
	Selenocysteine

(*) Essential only in certain cases.^[1]^[2]

(**) Pyrrolysine, sometimes considered "the 22nd amino acid", is not listed here as it is not used by humans. ^[3]

The amino acids regarded as essential for humans are phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, leucine, lysine, and histidine.^[4] Additionally, cysteine (or sulphur-containing amino acids), tyrosine (or aromatic amino acids), and arginine are required by infants and growing children.^[5]^[6] Essential amino acids are "essential" not because they are more important to life than the others, but because the body does not synthesize them, making it essential to include them in one's diet in order to obtain them. In addition, the amino acids arginine, cysteine, glycine, glutamine, histidine, proline, serine and tyrosine are considered conditionally essential, meaning they are not normally required in the diet, but must be supplied exogenously to specific populations that do not synthesize it in adequate amounts.^[1]^[2] An example would be with the disease phenylketonuria (PKU). Individuals living with PKU must keep their intake of phenylalanine extremely low to prevent mental retardation and other metabolic complications. However, they cannot synthesize tyrosine from phenylalanine, so tyrosine becomes essential in the diet of PKU patients.

The distinction between essential and non-essential amino acids is somewhat unclear, as some amino acids can be produced from others. The sulfur-containing amino acids, methionine and homocysteine, can be converted into each other but neither can be synthesized de novo in humans. Likewise, cysteine can be made from homocysteine but cannot be synthesized on its own. So, for convenience, sulfur-containing amino acids are sometimes considered a single pool of nutritionally-equivalent amino acids as are the aromatic amino acid pair, phenylalanine and tyrosine. Likewise arginine, ornithine, and citrulline, which are interconvertible by the urea cycle, are considered a single group.

Recommended daily amounts

Estimating the daily requirement for the indispensable amino acids has proven to be difficult; these numbers have undergone considerable revision over the last 20 years. The following table lists the WHO recommended daily amounts currently in use for essential amino acids in adult humans, together with their standard one-letter abbreviations.^[6]

Amino acid(s)	mg per kg body weight	mg per 70 kg	mg per 100 kg
H Histidine	10	700	1000
I Isoleucine	20	1400	2000
L Leucine	39	2730	3900
K Lysine	30	2100	3000
M Methionine + C Cysteine	10.4 + 4.1 (15 total)	1050	1500
F Phenylalanine + Y Tyrosine	25 (total)	1750	2500
T Threonine	15	1050	1500
W Tryptophan	4	280	400
V Valine	26	1820	2600

The recommended daily intakes for children aged three years and older is 10% to 20% higher than adult levels and those for infants can be as much as 150% higher in the first year of life.

Use of essential amino acids

At the level of the ribosome, the cells of eukaryotes require up to 21 different amino acids for protein synthesis. A shortfall of any one of these amino acids would thus be a limiting factor in protein synthesis. However, eukaryotes can synthesize some of these amino acids from other substrates. Consequently, only a subset of the amino acids used in protein synthesis are essential nutrients. Whether a particular amino acid is essential depends upon the species and the stage of development.

Scientists had known since the early 20th century that rats could not survive on a diet whose only protein source was zein, which comes from maize (corn), but recovered if they were fed casein from cow's milk. This led William Cumming Rose to the discovery of the essential amino acid threonine.^[7] Through manipulation of rodent diets, Rose was able to show that ten amino acids are essential for rats: lysine, tryptophan, histidine, phenylalanine, leucine, isoleucine, methionine, valine, and arginine, in addition to threonine. Rose's later work showed that eight amino acids are essential for adult human beings, with histidine also being essential for infants. Longer term studies established histidine is also essential for adult humans.^[8]

Because of the obvious difference in the nutritional value of zein versus casein in rat nutrition, various attempts have been made to express the "quality" or "value" of various kinds of protein. Measures include the biological value, net protein utilization, protein digestibility-corrected amino acid score. These concepts are important in the livestock industry, because the relative lack of one or more of the essential amino acids in animal feeds would have a limiting effect on growth and thus on feed conversion ratio. Thus, various feedstuffs may be fed in combination to increase net protein utilization, or a supplement of an individual amino acid (methionine, lysine, threonine, or tryptophan) can be added to the feed.

Although proteins from plant sources tend to have a relatively low biological value, in comparison to protein from eggs or milk, they are nevertheless "complete" in that they contain at least trace amounts of all of the amino acids that are essential in human nutrition.^[9] Eating various plant foods in combination can provide a protein of higher biological value.^[10]

Essential amino acid deficiency

The amino acids that are essential in the human diet were established in a series of experiments led by William Cumming Rose. The experiments involved elemental diets to healthy male graduate students. These diets consisted of cornstarch, sucrose, butterfat without protein, corn oil, inorganic salts, the known vitamins, a large brown "candy" made of liver extract flavored with peppermint oil (to supply any unknown vitamins), and mixtures of highly purified individual amino acids. The main outcome measure was nitrogen balance. Rose noted that the symptoms of nervousness, exhaustion, and dizziness were encountered to a greater or lesser extent whenever human subjects were deprived of an essential amino acid.^[11]

Essential amino acid deficiency should be distinguished from protein-energy malnutrition, which can manifest as marasmus or kwashiorkor. Kwashiorkor was once attributed to pure protein deficiency in individuals who were consuming enough calories ("sugar baby syndrome"). However, this theory has been challenged by the finding that there is no difference in the diets of children developing marasmus as opposed to kwashiorkor.^[12]

Mnemonics

Using the one-letter designation shown above, mnemonic devices have been developed for use in memorizing the essential amino acids. Previous devices have utilized the first letter of the amino acids' names, and in general did not include arginine which is not always essential. Mnemonic devices in common use are PVT TIM HaLL^[13] and TT HALL V(ery) IMP(ortant).^[14]

Alternative mnemonics based on the amino acids' assigned single letters include LIFT HIM KIW(V)I and TV FILM HW(R)K. Such mnemonics are preferable, since they avoid confusion between amino acids sharing the same first letter (Alanine, Arginine, Aspartic Acid and Asparagine, for example - only one of which, arginine, is a (conditionally) essential amino acid). Similar confusion arises between Thr, Tyr and Trp - only one of which (Tyr) is nonessential.

Another method uses the first letter of each essential amino acid to begin each word in a phrase, such as: "Any Help In Learning These Little Molecules Proves Truly Valuable."^[15] This method begins with the two amino acids that need some qualifications as to their requirements. Also, There as [a] fat man [that] hated vanilla icing, [but] loved Kit-Kats.

A useful mnemonic sentence using the single-letter code is: The Whole Food Larder Really Must Have Various Key Ingredients.

A medical student may find the following way useful as it distinguishes the glucogenic essential amino acids from the ketogenic essential amino acids:

Gluconeogenic (Val, Met, His, Arg) : "Val met his argumentative glucose"

Gluconeogenic/Ketogenic (Ile, Thr, Trp, Phe) : "Illy threw the tarp over the pheasant"

Ketogenic (Leu, Lys) : "Ketones in lieu of lysine"

References

^ ^a ^b Fürst P, Stehle P (1 June 2004). "What are the essential elements needed for the determination of amino acid requirements in humans?". Journal of Nutrition 134 (6 Suppl): 1558S–1565S. PMID 15173430. http://jn.nutrition.org/cgi/content/full/134/6/1558S.
^ ^a ^b Reeds PJ (1 July 2000). "Dispensable and indispensable amino acids for humans". J. Nutr. 130 (7): 1835S–40S. PMID 10867060. http://jn.nutrition.org/cgi/content/full/130/7/1835S.
^ Richard Cammack. "Newsletter 2009, Biochemical Nomenclature Committee of IUPAC and NC-IUBMB". http://www.chem.qmul.ac.uk/iubmb/newsletter/2009.html#item3.
^ Young VR (1994). "Adult amino acid requirements: the case for a major revision in current recommendations". J. Nutr. 124 (8 Suppl): 1517S–1523S. PMID 8064412. http://jn.nutrition.org/cgi/reprint/124/8_Suppl/1517S.pdf.
^ Imura K, Okada A (1998). "Amino acid metabolism in pediatric patients". Nutrition 14 (1): 143–8. doi:10.1016/S0899-9007(97)00230-X. PMID 9437700.
^ ^a ^b FAO/WHO/UNU (2007). "PROTEIN AND AMINO ACID REQUIREMENTS IN HUMAN NUTRITION". WHO Press. http://whqlibdoc.who.int/trs/WHO_TRS_935_eng.pdf. , page 150
^ Rose WC, Haines WJ, Warner DT, Johnson JE. The amino acid requirements of man. II. The role of threonine and histidine. J Biol Chem. 1951;188(1):49-58
^ J D Kopple and M E Swendseid (May 1975). "Evidence that histidine is an essential amino acid in normal and chronically uremic man.". J Clin Invest. 55 (5): 881–891. doi:10.1172/JCI108016. PMC 301830. PMID 1123426. http://www.jci.org/articles/view/108016.
^ McDougall J. Plant foods have a complete amino acid composition. Circulation. 2002;105(25):e197
^ Woolf, P. J.; Fu, L. L.; Basu, A. (2011). Haslam, Niall James. ed. "VProtein: Identifying Optimal Amino Acid Complements from Plant-Based Foods". PLoS ONE 6 (4): e18836. doi:10.1371/journal.pone.0018836. PMC 3081312. PMID 21526128. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3081312. edit
^ Rose WC, Haines WJ, Warner DT. The amino acid requirements of man. III. The role of isoleucine; additional evidence concerning histidine. J Biol Chem. 1951;193(2):605-612
^ Ahmed T, Rahman S, Cravioto A. Oedematous malnutrition. Indian J Med Res. 2009;130(5):651-654
^ Mnemonic at medicalmnemonics.com 442 128
^ ;MATT VIL PLy Essential amino acids Essential amino acids, Mnemonic.
^ Williams, R.A.D.; Eliot, J.C. (1989). Basic and Applied Dental Biochemistry. Elsevier Health Sciences. pp. 149. ISBN 0-443-03144-4.

External links

Amino acid content of some vegetarian foods - In a meal, make sure at least one food has a low value in each row of the "Amount to meet RDA" column, at veganhealth.org
Amino Acid Profiles of Some Common Feeds at Virginia Tech
Molecular Expressions: The Amino Acid Collection - Has detailed information and crystal photographs of each amino acid. at Florida State University
vProtein - An online software tool to analyze the essential amino acid profiles of single and pairs of plant based foods based on human requirements.

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English Journal

Total amino acid profiles of heat-processed fresh Elaeis guineensis and Raphia hookeri wines.

Ibegbulem CO, Igwe CU, Okwu GN, Ujowundu CO, Onyeike EN, Ayalogu EO.SourceDepartment of Biochemistry, Federal University of Technology, Owerri, Nigeria. Electronic address: ibemog@yahoo.com.
Food chemistry.Food Chem.2013 Jun 1;138(2-3):1616-20. doi: 10.1016/j.foodchem.2012.11.110. Epub 2012 Dec 5.
Total amino acid (AA) profiles of heat-processed fresh Elaeis guineensis and Raphia hookeri wines were studied. Heating their fresh wines to 85°C, cooling and diluting to original volumes distilled off ethanol, but did not change their moisture and nitrogen contents. R. hookeri wine contained more
PMID 23411289

Activation of a casB gene encoding β-glucosidase of Pectobacterium carotovorum subsp. carotovorum LY34.

Kim MK, An CL, Kang TH, Kim J, Kim H, Yun HD.SourceGyeongsangnam-do Agricultural Research and Extension Service, Chinju 660-360, Republic of Korea.
Microbiological research.Microbiol Res.2013 Mar 30;168(3):138-46. doi: 10.1016/j.micres.2012.10.004. Epub 2012 Nov 21.
Two cas genes were isolated from Pectobacterium carotovorum subsp. carotovorum LY34 (Pcc LY34). Sequence analysis of the 4873bp cloned DNA fragment (accession number AY866383) revealed two open reading frames (casF and casB) that are predicted to encode 658 and 467 amino acid proteins, respectively.
PMID 23176777

RNA-binding ability of FUS regulates neurodegeneration, cytoplasmic mislocalization and incorporation into stress granules associated with FUS carrying ALS-linked mutations.

Daigle JG, Lanson NA Jr, Smith RB, Casci I, Maltare A, Monaghan J, Nichols CD, Kryndushkin D, Shewmaker F, Pandey UB.AbstractAmyotrophic lateral sclerosis (ALS) is an uncommon neurodegenerative disease caused by degeneration of upper and lower motor neurons. Several genes, including SOD1, TDP-43, FUS, Ubiquilin 2, C9orf72 and Profilin 1, have been linked with the sporadic and familiar forms of ALS. FUS is a DNA/RNA-binding protein (RBP) that forms cytoplasmic inclusions in ALS and frontotemporal lobular degeneration (FTLD) patients' brains and spinal cords. However, it is unknown whether the RNA-binding ability of FUS is required for causing ALS pathogenesis. Here, we exploited a Drosophila model of ALS and neuronal cell lines to elucidate the role of the RNA-binding ability of FUS in regulating FUS-mediated toxicity, cytoplasmic mislocalization and incorporation into stress granules (SGs). To determine the role of the RNA-binding ability of FUS in ALS, we mutated FUS RNA-binding sites (F305L, F341L, F359L, F368L) and generated RNA-binding-incompetent FUS mutants with and without ALS-causing mutations (R518K or R521C). We found that mutating the aforementioned four phenylalanine (F) amino acids to leucines (L) (4F-L) eliminates FUS RNA binding. We observed that these RNA-binding mutations block neurodegenerative phenotypes seen in the fly brains, eyes and motor neurons compared with the expression of RNA-binding-competent FUS carrying ALS-causing mutations. Interestingly, RNA-binding-deficient FUS strongly localized to the nucleus of Drosophila motor neurons and mammalian neuronal cells, whereas FUS carrying ALS-linked mutations was distributed to the nucleus and cytoplasm. Importantly, we determined that incorporation of mutant FUS into the SG compartment is dependent on the RNA-binding ability of FUS. In summary, we demonstrate that the RNA-binding ability of FUS is essential for the neurodegenerative phenotype in vivo of mutant FUS (either through direct contact with RNA or through interactions with other RBPs).
Human molecular genetics.Hum Mol Genet.2013 Mar 15;22(6):1193-205. doi: 10.1093/hmg/dds526. Epub 2012 Dec 20.
Amyotrophic lateral sclerosis (ALS) is an uncommon neurodegenerative disease caused by degeneration of upper and lower motor neurons. Several genes, including SOD1, TDP-43, FUS, Ubiquilin 2, C9orf72 and Profilin 1, have been linked with the sporadic and familiar forms of ALS. FUS is a DNA/RNA-bindin
PMID 23257289

Japanese Journal

Two types of alcohol dehydrogenase from Perilla can form citral and perillaldehyde.

Sato-Masumoto Naoko,Ito Michiho
Phytochemistry 104, 12-20, 2014-08
… In this study, two types of alcohol dehydrogenases, an aldo-keto reductase (AKR) and a geraniol dehydrogenase (GeDH), which are thought to participate in the biosynthesis of perilla essential oil components, such as citral and perillaldehyde, were isolated from three pure lines of perilla. … These enzymes shared high amino acid sequence identity within the genus Perilla, and were expressed regardless of oil type. …
NAID 120005439534

Intracellular boron accumulation in CHO-K1 cells using amino acid transport control

Sato Eisuke,Yamamoto Tetsuya,Shikano Naoto,Ogura Masato,Nakai Kei,Yoshida Fumiyo,Uemae Yoji,Takada Tomoya,Isobe Tomonori,Matsumura Akira
Applied radiation and isotopes 88, 99-103, 2014-06
… BPA used in BNCT has a similar structure to some essential amino acids and is transported into tumor cells by amino acid transport systems. … CHO-K1 cells demonstrate system L (LAT1) activity and are suitable for specifying the transport system of a neutral amino acid. …
NAID 120005468402

A domain swapping approach to elucidate differential regiospecific hydroxylation by geraniol and linalool synthases from perilla.

Sato-Masumoto Naoko,Ito Michiho
Phytochemistry 102, 46-54, 2014-06
… Geraniol and linalool are acyclic monoterpenes found in plant essential oils that have attracted much attention for their commercial use and in pharmaceutical studies. … Both synthases are very similar at the amino acid level and share the same substrate; … Further, five amino acids in domain IV-4 were apparently indispensable for the formation of geraniol and linalool. …
NAID 120005439487