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この項目では、アミノ酸のグリシンについて記述しています。その他のグリシンについては「グリシン (曖昧さ回避)」をご覧ください。 |
| グリシン[1] |
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別称
Aminoethanoic acid
Aminoacetic acid
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| 識別情報 |
| 略称 |
Gly, G |
| CAS登録番号 |
56-40-6 |
| PubChem |
750 |
| ChemSpider |
730 |
| UNII |
TE7660XO1C |
| EINECS番号 |
200-272-2 |
| KEGG |
D00011 |
| ChEMBL |
CHEMBL773 |
| IUPHARリガンド |
727 |
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- InChI=1S/C2H5NO2/c3-1-2(4)5/h1,3H2,(H,4,5)
Key: DHMQDGOQFOQNFH-UHFFFAOYSA-N
InChI=1/C2H5NO2/c3-1-2(4)5/h1,3H2,(H,4,5)
Key: DHMQDGOQFOQNFH-UHFFFAOYAW
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| 特性 |
| 化学式 |
C2H5NO2 |
| モル質量 |
75.07 g mol−1 |
| 外観 |
白色の固体 |
| 密度 |
1.1607 g/cm3 |
| 融点 |
233 °C (分解)
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| 水への溶解度 |
25 g/100 mL |
| 溶解度 |
エタノール、ピリジンに可溶。エーテルには不溶。 |
| 酸解離定数 pKa |
2.34 (カルボキシル基), 9.6 (アミノ基)[2] |
| 危険性 |
| 半数致死量 LD50 |
2600 mg/kg (マウス；経口) |
| 特記なき場合、データは常温（25 °C）・常圧（100 kPa）におけるものである。 |
グリシン開裂、1はテトラヒドロ葉酸、2は5,10-メチレンテトラヒドロ葉酸
テトラヒドロ葉酸（THF）による代謝とビタミンB12によるTHFの再生産、de:Folsäure=葉酸、DHF=ジヒドロ葉酸、THF=テトラヒドロ葉酸、Vit.B12=ビタミンB12、Methyl-Vit.B12=メチルコバラミン、Methionin=メチオニン、Methionin Syntase=5-メチルテトラヒドロ葉酸-ホモシステインメチルトランスフェラーゼ、Homocystein=ホモシステイン、N5-Methyl-THF=5-メチルテトラヒドロ葉酸、N5,N10-Methylene-THF=5,10-メチレンテトラヒドロ葉酸、N10-Formyl-THF=10-ホルミルテトラヒドロ葉酸、dUMP=デオキシウリジン一リン酸、NADPH、DNA
グリシン (glycine) とは、アミノ酢酸のことで、タンパク質を構成するアミノ酸の中で最も単純な形を持つ。別名グリココル。糖原性アミノ酸である。 示性式は H2NCH2COOH、不斉炭素を持たないため、生体を構成する α-アミノ酸の中では唯一 D-, L- の立体異性がない。非極性側鎖アミノ酸に分類される。
多くの種類のタンパク質ではグリシンはわずかしか含まれていないが、ゼラチンやエラスチンといった、動物性タンパク質のうちコラーゲンと呼ばれるものに多く（全体の3分の1くらい）含まれる。
1820年にフランス人化学者アンリ・ブラコノーによりゼラチンから単離された。 甘かったことからギリシャ語で甘いを意味する glykys に因んで glycocoll と名付けられ、後に glycine に改名された。
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目次
- 1 生合成・代謝
- 2 生体内での利用
- 3 物性
- 4 神経伝達物質と高グリシン血症
- 5 出典
- 6 関連項目
- 7 外部リンク
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生合成・代謝
グリシン開裂系はテトラヒドロ葉酸により以下の反応でグリシンを開裂する[3][要高次出典]。
- テトラヒドロ葉酸 + グリシン + NAD+ = 5,10-メチレンテトラヒドロ葉酸+ NH3 + CO2 + NADH + H+
グリシン開裂系とは別に、グリシンヒドロキシメチルトランスフェラーゼ（セリンヒドロキシメチルトランスフェラーゼ）（EC 2.1.2.1）の働きにより、可逆的にグリシンをL-セリンに相互に変換し、5,10-メチレンテトラヒドロ葉酸をテトラヒドロ葉酸に変換する反応が触媒される[4][5]。
- 5,10-メチレンテトラヒドロ葉酸+ グリシン + H2O = テトラヒドロ葉酸 + L-セリン [6]
グリシン開裂系とセリンヒドロキシメチルトランスフェラーゼによる２つの反応を複合すると以下の反応式が示めされる。また、その全容は図の通りである。
- 2 グリシン + NAD+ + H2O → セリン + CO2 + NH3 + NADH + H+
グリシンが仮に脱アミノ化を受けるとグリコール酸が生成し、酸化を受けるとグリオキシル酸が生成するが、グリオキシル酸はヒトではエチレングリコールからシュウ酸に代謝される際の中間体で、酸化を受けると有害なシュウ酸が生成されることになる[7][8]。その反応を回避する観点から、グリシンの代謝は重要な意義がある。
生体内での利用
グリシンは様々な生体物質の原料として利用されている。一部を以下に示す。
- コラーゲンタンパク質のペプチド鎖を構成するアミノ酸は、"―（グリシン）―（アミノ酸X）―（アミノ酸Y）―" と、グリシンが3残基ごとに繰り返す一次構造を有する。この配列は、コラーゲン様配列と呼ばれ、コラーゲンタンパク質の特徴である。
- 動物においてはグリシンおよびスクシニルCoAからアミノレブリン酸合成酵素（EC 2.3.1.37）の作用でアミノレブリン酸が合成され、これを原料にポルフィリンが合成され、ヘムとして利用される。
- グルタチオンはグルタミン酸、システイン、グリシンが、この順番でペプチド結合したトリペプチドである 。生体内で抗酸化物質として機能する。
- アルギニンとグリシンから、グリシンアミジノトランスフェラーゼ(EC 2.1.4.1)、グアニジノ酢酸-N-メチルトランスフェラーゼ (EC 2.1.1.2) 、クレアチンキナーゼ (EC 2.7.3.2)の作用により、クレアチンリン酸として合成される。この反応は腎臓と肝臓にて行われる。クレアチンは、筋肉中に存在しエネルギー源として貯蔵される。
物性
- 分子量 75.07
- 等電点 5.97
- 溶解性 水・蟻酸に易溶、エタノールに不溶
- 溶解度（水、g/100g）22.5 (20℃)、33.2 (40℃)、45.3 (60℃)
- ファンデルワールス半径 48
- 味甘（閾値 1.1 mg/ml）
神経伝達物質と高グリシン血症
中枢神経系においてグリシンはGABAに次いで重要な抑制性神経伝達物質である。今のところグリシンの受容体として知られているものは全てイオンチャネル型であり、グリシンが結合すると内蔵しているCl−チャネルの透過性が増えてCl−が細胞内に流れ込み抑制性シナプス後電位（IPSP）を発生させる。痙攣誘発剤であるストリキニンはグリシン受容体に対する特異的な阻害薬である。一方で、興奮性神経伝達物質としての役割も知られている。グリシンはNMDA受容体に存在するグリシン結合部位に作用し、チャネルの開口を補助する。グリシン受容体に対しては約100uM, NMDA受容体に対しては約100nM～1uMのED50を示すとされている。
脳や肝臓に存在するグリシン開裂系の酵素の遺伝的な欠損により、体液中や脳にグリシンが大量に蓄積することにより発症する先天性アミノ酸代謝異常症のひとつである高グリシン血症を引き起こす。グリシンは中枢神経系で神経伝達物質として働くため、グリシン蓄積が重篤な神経障害をもたらす[9]。
葉酸の触媒過程の全容において、平衡がテトラヒドロ葉酸側に偏っており、テトラヒドロ葉酸から5,10-メチレンテトラヒドロ葉酸を供給するグリシン開裂系は葉酸系の代謝過程で重要な役割を果たしている。
出典
- ^ The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (第11 ed.), Merck, (1989), ISBN 091191028X , 4386.
- ^ Dawson, R.M.C., et al., Data for Biochemical Research, Oxford, Clarendon Press, 1959.
- ^ アミノ酸の分解 講義資料のページ
- ^ Appaji Rao N, Ambili M, Jala VR, Subramanya HS, Savithri HS (April 2003). “Structure-function relationship in serine hydroxymethyltransferase”. Biochim. Biophys. Acta 1647 (1-2): 24–9. PMID 12686103.
- ^ Stover P, Schirch V (August 1990). “Serine hydroxymethyltransferase catalyzes the hydrolysis of 5,10-methenyltetrahydrofolate to 5-formyltetrahydrofolate”. J. Biol. Chem. 265 (24): 14227–33. PMID 2201683.
- ^ http://www.genome.jp/dbget-bin/www_bget?enzyme+2.1.2.1
- ^ http://www.safe.nite.go.jp/management/data/34/8.html [リンク切れ]
- ^ Carney, E.W. (1994) An integrated perspective on the developmental toxicity of ethylene glycol. Reprod. Toxicol. 8, 99-113
- ^ 高グリシン血症 （難病情報センター）
関連項目
- ザルコシン
- グリシンベタイン
- クレアチン
- グルタチオン
- 5,10-メチレンテトラヒドロ葉酸
- テトラヒドロ葉酸
- グリシン開裂系
外部リンク
- グリシン - 「健康食品」の安全性・有効性情報 （国立健康・栄養研究所）
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タンパク質を構成するアミノ酸 |
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| ヒトの必須アミノ酸 |
トリプトファン - リシン - メチオニン - フェニルアラニン - トレオニン - バリン - イソロイシン - ロイシン - ヒスチジン
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| ヒトの非必須アミノ酸 |
アラニン - アルギニン - アスパラギン - セリン - アスパラギン酸 - システイン - グルタミン - グルタミン酸 - グリシン - プロリン - チロシン
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| 語句 |
アミノ酸合成 - アミノ酸の代謝分解 - アミノ酸発酵 - 必須アミノ酸 - ペプチド - コドン - GABA - ケト原性アミノ酸 - 糖原性アミノ酸
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主要な生体物質
ペプチド - アミノ酸 - 核酸 - 炭水化物 - 脂肪酸 - テルペノイド - カロテノイド
テトラピロール - 補因子 - ステロイド - フラボノイド - アルカロイド - ポリケチド - 配糖体 |
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For the plant, see Glycine (plant).
| Glycine[1] |
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Other names
Aminoethanoic acid
Aminoacetic acid
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| Identifiers |
| Abbreviations |
Gly, G |
| CAS number |
56-40-6 Y |
| PubChem |
750 |
| ChemSpider |
730 Y |
| UNII |
TE7660XO1C Y |
| EC-number |
200-272-2 |
| DrugBank |
DB00145 |
| KEGG |
D00011 Y |
| ChEBI |
CHEBI:15428 Y |
| ChEMBL |
CHEMBL773 Y |
| IUPHAR ligand |
727 |
| ATC code |
B05CX03 |
| Jmol-3D images |
Image 1 |
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-
InChI=1S/C2H5NO2/c3-1-2(4)5/h1,3H2,(H,4,5) Y
Key: DHMQDGOQFOQNFH-UHFFFAOYSA-N Y
InChI=1/C2H5NO2/c3-1-2(4)5/h1,3H2,(H,4,5)
Key: DHMQDGOQFOQNFH-UHFFFAOYAW
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| Properties |
| Molecular formula |
C2H5NO2 |
| Molar mass |
75.07 g mol−1 |
| Appearance |
white solid |
| Density |
1.607 g/cm3 |
| Melting point |
233 °C (decomposition)
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| Solubility in water |
24.99 g/100 mL (25 °C)[2] |
| Solubility |
soluble in ethanol, pyridine
insoluble in ether |
| Acidity (pKa) |
2.34 (carboxyl), 9.6 (amino)[3] |
| Hazards |
| MSDS |
External MSDS |
| LD50 |
2600 mg/kg (mouse, oral) |
| Supplementary data page |
Structure and
properties |
n, εr, etc. |
Thermodynamic
data |
Phase behaviour
Solid, liquid, gas |
| Spectral data |
UV, IR, NMR, MS |
Y (verify) (what is: Y/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
| Infobox references |
Glycine (abbreviated as Gly or G)[4] is an organic compound with the formula NH2CH2COOH. Having a hydrogen substituent as its side-chain, glycine is the smallest of the 20 amino acids commonly found in proteins. Its codons are GGU, GGC, GGA, GGG cf. the genetic code.
Glycine is a colourless, sweet-tasting crystalline solid. It is unique among the proteinogenic amino acids in that it is not chiral. It can fit into hydrophilic or hydrophobic environments, due to its minimal side chain of only one hydrogen atom. Glycine is also the genus name of the Soybean plant (species name = Glycine max).
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Contents
- 1 Production and key properties
- 2 Biosynthesis
- 3 Degradation
- 4 Physiological function
- 4.1 As a biosynthetic intermediate
- 4.2 As a neurotransmitter
- 5 Commercial uses
- 5.1 Animal and human foods
- 5.2 Cosmetics and miscellaneous applications
- 5.3 Chemical feedstock
- 6 Presence in space
- 7 See also
- 8 References
- 9 Further reading
- 10 External links
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Production and key properties
Glycine was discovered in 1820, by Henri Braconnot who boiled gelatin with sulfuric acid.[5]
Glycine is manufactured industrially by treating chloroacetic acid with ammonia:[6]
- ClCH2COOH + 2 NH3 → H2NCH2COOH + NH4Cl
About 15 million kg are produced annually in this way.[7]
In the USA (by GEO Specialty Chemicals, Inc.) and in Japan (by Shoadenko), glycine is produced via the Strecker amino acid synthesis.[8][9]
There are two producers of glycine in the United States: Chattem Chemicals, Inc., a subsidiary of Mumbai-based Sun Pharmaceutical, and GEO Specialty Chemicals, Inc., which purchased the glycine and naphthalene sulfonate production facilities of Hampshire Chemical Corp, a subsidiary of Dow Chemical.[8][10]
Chattem's manufacturing process ("MCA" process) occurs in batches and results in a finished product with some residual chloride but no sulfate, while GEO’s manufacturing process is considered a semi-batch process and results in a finished product with some residual sulfate but no chloride.
Its pKA values are 2.35 and 9.78, so above pH 9.78, most of the glycine exists as the anionic amine, H2NCH2CO2-. Below pH 2.35, its solutions contain mostly the cationic carboxylic acid H3N+CH2CO2H. Its isoelectric point (pI) is 6.06.
Glycine exists in zwitterionic form in solution. In this form, the partial charges on different atoms as determined using Gasteiger charge method are given as follows: N (+0.2358), H (attached to N) (+0.1964), alpha-C (+0.001853), H (attached to alpha-C) (+0.08799), carbonyl C (+0.085) and carbonyl O (-0.5445).
Biosynthesis
Glycine is not essential to the human diet, as it is biosynthesized in the body from the amino acid serine, which is in turn derived from 3-phosphoglycerate. In most organisms, the enzyme Serine hydroxymethyltransferase catalyses this transformation via the cofactor pyridoxal phosphate:[11]
- serine + tetrahydrofolate → glycine + N5,N10-Methylene tetrahydrofolate + H2O
In the liver of vertebrates, glycine synthesis is catalyzed by glycine synthase (also called glycine cleavage enzyme). This conversion is readily reversible:[11]
- CO2 + NH4+ + N5,N10-Methylene tetrahydrofolate + NADH + H+ → Glycine + tetrahydrofolate + NAD+
Glycine is coded by codons GGU, GGC, GGA and GGG. Most proteins incorporate only small quantities of glycine. A notable exception is collagen, which contains about 35% glycine.[11][12]
Degradation
Glycine is degraded via three pathways. The predominant pathway in animals and plants involves the glycine cleavage enzyme[11]
- Glycine + tetrahydrofolate + NAD+ → CO2 + NH4+ + N5,N10-Methylene tetrahydrofolate + NADH + H+
In the second pathway, glycine is degraded in two steps. The first step is the reverse of glycine biosynthesis from serine with serine hydroxymethyl transferase. Serine is then converted to pyruvate by serine dehydratase.[11]
In the third pathway of glycine degradation, glycine is converted to glyoxylate by D-amino acid oxidase. Glyoxylate is then oxidized by hepatic lactate dehydrogenase to oxalate in an NAD+-dependent reaction.[11]
The half-life of glycine and its elimination from the body varies significantly based on dose. In one study, the half-life was between 0.5 and 4.0 hours. [13]
Physiological function
The principal function of glycine is as a precursor to proteins. It is also a building block to numerous natural products.
As a biosynthetic intermediate
In higher eukaryotes, D-Aminolevulinic acid, the key precursor to porphyrins, is biosynthesized from glycine and succinyl-CoA. Glycine provides the central C2N subunit of all purines.[11]
As a neurotransmitter
Glycine is an inhibitory neurotransmitter in the central nervous system, especially in the spinal cord, brainstem, and retina. When glycine receptors are activated, chloride enters the neuron via ionotropic receptors, causing an Inhibitory postsynaptic potential (IPSP). Strychnine is a strong antagonist at ionotropic glycine receptors, whereas bicuculline is a weak one. Glycine is a required co-agonist along with glutamate for NMDA receptors. In contrast to the inhibitory role of glycine in the spinal cord, this behaviour is facilitated at the (NMDA) glutaminergic receptors which are excitatory.[14] The LD50 of glycine is 7930 mg/kg in rats (oral),[15] and it usually causes death by hyperexcitability.
There is some evidence showing that 3000 milligrams of glycine before bedtime improves sleep quality.[16][non-primary source needed]
Commercial uses
In the US, glycine is typically sold in two grades: United States Pharmacopeia (“USP”), and technical grade. Most glycine is manufactured as USP grade material for diverse uses. USP grade sales account for approximately 80 to 85 percent of the U.S. market for glycine.
- Pharmaceutical grade glycine is produced for some pharmaceutical applications, such as intravenous injections, where the customer’s purity requirements often exceed the minimum required under the USP grade designation. Pharmaceutical grade glycine is often produced to proprietary specifications and is typically sold at a premium over USP grade glycine.
- Technical grade glycine, which may or may not meet USP grade standards, is sold for use in industrial applications; e.g., as an agent in metal complexing and finishing. Technical grade glycine is typically sold at a discount to USP grade glycine.[17]
Animal and human foods
Other markets for USP grade glycine include its use an additive in pet food and animal feed. For humans, glycine is sold as a sweetener/taste enhancer. Food supplements and protein drinks contain glycine. Certain drug formulations include glycine to improve gastric absorption of the drug.
Cosmetics and miscellaneous applications
Glycine serves as a buffering agent in antacids, analgesics, antiperspirants, cosmetics, and toiletries.
Many miscellaneous products use glycine or its derivatives, such as the production of rubber sponge products, fertilizers, metal complexants.[18]
Zwitterionic salt (right) of glycine at neutral pH
Chemical feedstock
Glycine is an intermediate in the synthesis of a variety of chemical products. It is used in the manufacture of the herbicide glyphosate. Glyphosate is a non-selective systemic herbicide used to kill weeds, especially perennials and broadcast or used in the cut-stump treatment as a forestry herbicide. Initially, glyphosate was sold only by Monsanto under the tradename Roundup, but is no longer under patent.
Presence in space
The detection of glycine in the interstellar medium has been debated.[19] In 2008, the glycine-like molecule aminoacetonitrile was discovered in the Large Molecule Heimat, a giant gas cloud near the galactic center in the constellation Sagittarius by the Max Planck Institute for Radio Astronomy.[20] In 2009, glycine sampled in 2004 from comet Wild 2 by the NASA spacecraft Stardust was confirmed, the first discovery of extraterrestrial glycine. That mission's results bolstered the theory of panspermia, which claims that the "seeds" of life are widespread throughout the universe.[21]
See also
References
- ^ The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (11th ed.), Merck, 1989, ISBN 091191028X, 4386.
- ^ http://prowl.rockefeller.edu/aainfo/solub.htm
- ^ Dawson, R.M.C., et al., Data for Biochemical Research, Oxford, Clarendon Press, 1959.
- ^ "Nomenclature and symbolism for amino acids and peptides (IUPAC-IUB Recommendations 1983)", Pure Appl. Chem. 56 (5): 595–624, 1984, doi:10.1351/pac198456050595.
- ^ R.H.A. Plimmer (1912) [1908]. R.H.A. Plimmer & F.G. Hopkins. ed. The chemical composition of the proteins. Monographs on biochemistry. Part I. Analysis (2nd ed.). London: Longmans, Green and Co.. p. 82. http://books.google.com/?id=7JM8AAAAIAAJ&pg=PA112. Retrieved January 18, 2010.
- ^ Ingersoll, A. W.; Babcock, S. H. (1932), "Hippuric acid", Org. Synth. 12: 40, http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv2p0328; Coll. Vol. 2: 328.
- ^ Karlheinz Drauz, Ian Grayson, Axel Kleemann, Hans-Peter Krimmer, Wolfgang Leuchtenberger, Christoph Weckbecker “Amino Acids” in Ullmann's Encyclopedia of Industrial Chemistry 2007, Wiley-VCH, Weinheim. doi:10.1002/14356007.a02_057.pub2
- ^ a b http://www.usitc.gov/trade_remedy/731_ad_701_cvd/investigations/2007/glycine_from_india_japan_korea/preliminary/DOC/Glycine%20Conference%20(prelim).wpd
- ^ http://www.geosc.com/consumeradditives/default.aspx
- ^ U.S. International Trade Commission, "Glycine From China." Investigation No. 731-TA-718 (Second Review), Publication No. 3810, October 2005
- ^ a b c d e f g Nelson, David L.; Cox, Michael M. (2005), Principles of Biochemistry (4th ed.), New York: W. H. Freeman, pp. 127, 675–77, 844, 854, ISBN 0-7167-4339-6.
- ^ Szpak, Paul (2011). "Fish bone chemistry and ultrastructure: implications for taphonomy and stable isotope analysis". Journal of Archaeological Science 38 (12): 3358–3372. doi:10.1016/j.jas.2011.07.022. http://uwo.academia.edu/PaulSzpak/Papers/827788/Fish_Bone_Chemistry_and_Ultrastructure_Implications_for_Taphonomy_and_Stable_Isotope_Analysis.
- ^ Hahn RG (1993). "Dose-dependent half-life of glycine". Urological Research 21 (4): 289–291. doi:10.1007/BF00307714. PMID 8212419.
- ^ "Recent development in NMDA receptors". Chinese Medical Journal. 2000. http://www.cmj.org/Periodical/paperlist.asp?id=LW7347&linkintype=pubmed.
- ^ "Safety (MSDS) data for glycine". The Physical and Theoretical Chemistry Laboratory Oxford University. 2005. http://physchem.ox.ac.uk/MSDS/GL/glycine.html. Retrieved 2006-11-01.
- ^ Yamadera W, Inagawa K, Chiba S, Bannai M, Takahashi M, Nakayama K (2007). "Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes". Sleep and Biological rhythms 5 (2): 126–131. doi:10.1111/j.1479-8425.2007.00262.x.
- ^ http://www.usitc.gov/publications/701_731/pub3980.pdf
- ^ "Notice of Preliminary Determination of Sales at Less Than Fair Value: Glycine From India" Federal Register 72 (7 November 2007): 62827.
- ^ Snyder LE, Lovas FJ, Hollis JM, et al. (2005). "A rigorous attempt to verify interstellar glycine". Astrophys J 619 (2): 914–930. arXiv:astro-ph/0410335. Bibcode 2005ApJ...619..914S. doi:10.1086/426677.
- ^ Staff. "Organic Molecule, Amino Acid-Like, Found In Constellation Sagittarius 27 March 2008 - Science Daily". http://www.sciencedaily.com/releases/2008/03/080326161658.htm. Retrieved 2008-09-16.
- ^ Reuters (18 August 2009). "Building block of life found on comet - Thomson Reuters 2009". http://www.reuters.com/article/scienceNews/idUSTRE57H02I20090818. Retrieved 2009-08-18.
Further reading
On attempts to detect glycine in interstellar medium
- Kuan YJ, Charnley SB, Huang HC, et al. (2003). "Interstellar glycine". Astrophys J 593 (2): 848–867. Bibcode 2003ApJ...593..848K. doi:10.1086/375637.
- Rachel Nowak. "Amino acid found in deep space - 18 July 2002 - New Scientist". http://www.newscientist.com/news/news.jsp?id=ns99992558. Retrieved 2007-07-01.
External links
- Glycine at PDRHealth.com
- Glycine cleavage system
- Glycine Therapy - A New Direction for Schizophrenia Treatment?
- "Organic Molecule, Amino Acid-Like, Found In Constellation Sagittarius". ScienceDaily. 27 March 2008. http://www.sciencedaily.com/releases/2008/03/080326161658.htm.
- Guochuan E. Tsai (1 December 2008). "A New Class of Antipsychotic Drugs: Enhancing Neurotransmission Mediated by NMDA Receptors". Psychiatric Times 25 (14). http://www.psychiatrictimes.com/display/article/10168/1357569.
- ChemSub Online (Glycine).
- NASA scientists have discovered glycine, a fundamental building block of life, in samples of comet Wild 2 returned by NASA's Stardust spacecraft.
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The 20 common amino acids
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| By properties |
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Aliphatic
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- Branched-chain amino acids (Valine
- Isoleucine
- Leucine)
- Methionine
- Alanine
- Proline
- Glycine
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Aromatic
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- Phenylalanine
- Tyrosine
- Tryptophan
- Histidine
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Polar, uncharged
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- Asparagine
- Glutamine
- Serine
- Threonine
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Positive charge (pKa)
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- Lysine (≈10.8)
- Arginine (≈12.5)
- Histidine (≈6.1)
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Negative charge (pKa)
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- Aspartic acid (≈3.9)
- Glutamic acid (≈4.1)
- Cysteine (≈8.3)
- Tyrosine (≈10.1)
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General
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- Essential amino acid
- Protein
- Peptide
- Genetic code
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| Other classifications |
- Essential amino acids
- Ketogenic amino acid
- Glucogenic amino acid
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- biochemical families: carbohydrates
- alcohols
- glycoproteins
- glycosides
- lipids
- eicosanoids
- fatty acids / intermediates
- phospholipids
- sphingolipids
- steroids
- nucleic acids
- constituents / intermediates
- proteins
- amino acids / intermediates
- tetrapyrroles / intermediates
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Amino acid metabolism metabolic intermediates
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| K→acetyl-CoA |
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lysine→
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- Saccharopine
- Allysine
- α-Aminoadipic acid
- α-Aminoadipate
- Glutaryl-CoA
- Glutaconyl-CoA
- Crotonyl-CoA
- β-Hydroxybutyryl-CoA
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leucine→
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- α-Ketoisocaproic acid
- Isovaleryl-CoA
- 3-Methylcrotonyl-CoA
- 3-Methylglutaconyl-CoA
- HMG-CoA
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tryptophan→alanine→
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- N'-Formylkynurenine
- Kynurenine
- Anthranilic acid
- 3-Hydroxykynurenine
- 3-Hydroxyanthranilic acid
- 2-Amino-3-carboxymuconic semialdehyde
- 2-Aminomuconic semialdehyde
- 2-Aminomuconic acid
- Glutaryl-CoA
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| G |
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G→pyruvate→citrate
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glycine→serine→
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- glycine→creatine: Glycocyamine
- Phosphocreatine
- Creatinine
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G→glutamate→
α-ketoglutarate
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histidine→
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- Urocanic acid
- Imidazol-4-one-5-propionic acid
- Formiminoglutamic acid
- Glutamate-1-semialdehyde
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proline→
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- 1-Pyrroline-5-carboxylic acid
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arginine→
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- Ornithine
- Putrescine
- Agmatine
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other
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- cysteine+glutamate→glutathione: γ-Glutamylcysteine
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G→propionyl-CoA→
succinyl-CoA
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valine→
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- α-Ketoisovaleric acid
- Isobutyryl-CoA
- Methacrylyl-CoA
- 3-Hydroxyisobutyryl-CoA
- 3-Hydroxyisobutyric acid
- 2-Methyl-3-oxopropanoic acid
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isoleucine→
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- 2,3-Dihydroxy-3-methylpentanoic acid
- 2-Methylbutyryl-CoA
- Tiglyl-CoA
- 2-Methylacetoacetyl-CoA
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methionine→
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- generation of homocysteine: S-Adenosyl methionine
- S-Adenosyl-L-homocysteine
- Homocysteine
- conversion to cysteine: Cystathionine
- alpha-Ketobutyric acid+Cysteine
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threonine→
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propionyl-CoA→
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G→fumarate
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phenylalanine→tyrosine→
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- 4-Hydroxyphenylpyruvic acid
- Homogentisic acid
- 4-Maleylacetoacetate
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G→oxaloacetate
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| Other |
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mt, k, c/g/r/p/y/i, f/h/s/l/o/e, a/u, n, m
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k, cgrp/y/i, f/h/s/l/o/e, au, n, m, epon
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m (A16/C10), i (k, c/g/r/p/y/i, f/h/s/o/e, a/u, n, m)
|
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- biochemical families: carbohydrates
- alcohols
- glycoproteins
- glycosides
- lipids
- eicosanoids
- fatty acids / intermediates
- phospholipids
- sphingolipids
- steroids
- nucleic acids
- constituents / intermediates
- proteins
- amino acids / intermediates
- tetrapyrroles / intermediates
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Neurotransmitters
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| Amino acids |
- Alanine
- Aspartate
- Cycloserine
- DMG
- GABA
- Glutamate
- Glycine
- Hypotaurine
- Kynurenic acid (Transtorine)
- NAAG (Spaglumic acid)
- NMG (Sarcosine)
- Serine
- Taurine
- TMG (Betaine)
|
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| Endocannabinoids |
- 2-AG
- 2-AGE (Noladin ether)
- AEA (Anandamide)
- NADA
- OAE (Virodhamine)
- Oleamide
- PEA (Palmitoylethanolamide)
- RVD-Hpα
- Hp (Hemopressin)
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| Gasotransmitters |
- Carbon monoxide
- Hydrogen sulfide
- Nitric oxide
- Nitrous oxide
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| Monoamines |
Dopamine
- Epinephrine (Adrenaline)
- Melatonin
- NAS (Normelatonin)
- Norepinephrine (Noradrenaline)
- Serotonin (5-HT)
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| Purines |
|
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| Trace amines |
- 3-ITA
- 5-MeO-DMT
- Bufotenin
- DMT
- m-Octopamine
- p-Octopamine
- m-Tyramine
- p-Tyramine
- NMT
- Phenethylamine
- Synephrine
- Thyronamine
- Tryptamine
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| Others |
- 1,4-BD
- Acetylcholine
- GBL
- GHB
- Histamine
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See also Template:Neuropeptides
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anat (h/r/t/c/b/l/s/a)/phys (r)/devp/prot/nttr/nttm/ntrp
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noco/auto/cong/tumr, sysi/epon, injr
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Glycinergics
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Receptor
ligands |
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Agonists
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- Alanine
- Cycloserine
- Dimethylglycine
- Glycine
- Hypotaurine
- Methylglycine (Sarcosine)
- Milacemide
- Quisqualamine
- Serine
- Taurine
- Trimethylglycine (Betaine)
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Antagonists
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- Bicuculline
- Brucine
- Caffeine
- Picrotoxin
- Pitrazepin
- Strychnine
- Thiocolchicoside
- Tutin
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Reuptake
inhibitors |
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Plasmalemmal
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GlyT1 inhibitors
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GlyT2 inhibitors
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Vesicular
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Enzyme
inhibitors |
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Anabolism/Catabolism
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SHMT Inhibitors
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GDC Inhibitors
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DAAO Inhibitors
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| Others |
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Precursors
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- 3-Phosphoglyceric acid
- Serine
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Cofactors
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- Vitamin B6 (Pyridoxine
- pyridoxamine
- pyridoxal → pyridoxal phosphate)
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