Glycine

(Redirected from Gly)

Glycine (symbol Gly or G;[6] /ˈɡlsn/ )[7] is an amino acid that has a single hydrogen atom as its side chain. It is the simplest stable amino acid (carbamic acid is unstable). Glycine is one of the proteinogenic amino acids. It is encoded by all the codons starting with GG (GGU, GGC, GGA, GGG).[8] Glycine is integral to the formation of alpha-helices in secondary protein structure due to the "flexibility" caused by such a small R group. Glycine is also an inhibitory neurotransmitter[9] – interference with its release within the spinal cord (such as during a Clostridium tetani infection) can cause spastic paralysis due to uninhibited muscle contraction.[10]

Glycine[1]
Skeletal formula of neutral glycine
Skeletal formula of zwitterionic glycine
Ball-and-stick model of the gas-phase structure
Ball-and-stick model of the zwitterionic solid-state structure
Space-filling model of the gas-phase structure
Space-filling model of the zwitterionic solid-state structure
Names
IUPAC name
Glycine
Systematic IUPAC name
Aminoacetic acid[2]
Other names
  • 2-Aminoethanoic acid
  • Glycocol
  • Glycic acid
  • Dicarbamic acid
Identifiers
3D model (JSmol)
Abbreviations Gly, G
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.000.248 Edit this at Wikidata
EC Number
  • 200-272-2
  • 227-841-8
E number E640 (flavour enhancer)
KEGG
UNII
  • InChI=1S/C2H5NH2/c3-1-2(4)5/h1,3H2,(H,4,5) checkY
    Key: DHMQDGOQFOQNFH-UHFFFAOYSA-N checkY
  • InChI=1S/C2H5NO2/c3-1-2(4)5/h1,3H2,(H,4,5)
    Key: DHMQDGOQFOQNFH-UHFFFAOYAW
  • C(C(=O)O)N
  • Zwitterion: C(C(=O)[O-])[NH3+]
  • C(C(=O)O)N.Cl
Properties
C2H5NO2
Molar mass 75.067 g·mol−1
Appearance White solid
Density 1.1607 g/cm3[3]
Melting point 233 °C (451 °F; 506 K) (decomposition)
249.9 g/L (25 °C)[4]
Solubility soluble in pyridine
sparingly soluble in ethanol
insoluble in ether
Acidity (pKa) 2.34 (carboxyl), 9.6 (amino)[5]
-40.3·10−6 cm3/mol
Pharmacology
B05CX03 (WHO)
Hazards
Lethal dose or concentration (LD, LC):
2600 mg/kg (mouse, oral)
Supplementary data page
Glycine (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

It is the only achiral proteinogenic amino acid.[11] It can fit into hydrophilic or hydrophobic environments, due to its minimal side chain of only one hydrogen atom.[12]

History and etymology

edit

Glycine was discovered in 1820 by French chemist Henri Braconnot when he hydrolyzed gelatin by boiling it with sulfuric acid.[13] He originally called it "sugar of gelatin",[14][15] but French chemist Jean-Baptiste Boussingault showed in 1838 that it contained nitrogen.[16] In 1847 American scientist Eben Norton Horsford, then a student of the German chemist Justus von Liebig, proposed the name "glycocoll";[17][18] however, the Swedish chemist Berzelius suggested the simpler current name a year later.[19][20] The name comes from the Greek word γλυκύς "sweet tasting"[21] (which is also related to the prefixes glyco- and gluco-, as in glycoprotein and glucose). In 1858, the French chemist Auguste Cahours determined that glycine was an amine of acetic acid.[22]

Production

edit

Although glycine can be isolated from hydrolyzed proteins, this route is not used for industrial production, as it can be manufactured more conveniently by chemical synthesis.[23] The two main processes are amination of chloroacetic acid with ammonia, giving glycine and hydrochloric acid,[24] and the Strecker amino acid synthesis,[25] which is the main synthetic method in the United States and Japan.[26] About 15 thousand tonnes are produced annually in this way.[27]

Glycine is also co-generated as an impurity in the synthesis of EDTA, arising from reactions of the ammonia co-product.[28]

Chemical reactions

edit

Its acid–base properties are most important. In aqueous solution, glycine is amphoteric: below pH = 2.4, it converts to the ammonium cation called glycinium. Above about pH 9.6, it converts to glycinate.

 

Glycine functions as a bidentate ligand for many metal ions, forming amino acid complexes.[29] A typical complex is Cu(glycinate)2, i.e. Cu(H2NCH2CO2)2, which exists both in cis and trans isomers.[30][31]

With acid chlorides, glycine converts to the amidocarboxylic acid, such as hippuric acid[32] and acetylglycine.[33] With nitrous acid, one obtains glycolic acid (van Slyke determination). With methyl iodide, the amine becomes quaternized to give trimethylglycine, a natural product:

H
3
N+
CH
2
COO
+ 3 CH3I → (CH
3
)
3
N+
CH
2
COO
+ 3 HI

Glycine condenses with itself to give peptides, beginning with the formation of glycylglycine:[34]

2 H
3
N+
CH
2
COO
H
3
N+
CH
2
CONHCH
2
COO
+ H2O

Pyrolysis of glycine or glycylglycine gives 2,5-diketopiperazine, the cyclic diamide.[35]

Glycine forms esters with alcohols. They are often isolated as their hydrochloride, such as glycine methyl ester hydrochloride. Otherwise, the free ester tends to convert to diketopiperazine.

As a bifunctional molecule, glycine reacts with many reagents. These can be classified into N-centered and carboxylate-center reactions.

Metabolism

edit

Biosynthesis

edit

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:[36]

serine + tetrahydrofolate → glycine + N5,N10-methylene tetrahydrofolate + H2O

In E. coli, glycine is sensitive to antibiotics that target folate.[37]

In the liver of vertebrates, glycine synthesis is catalyzed by glycine synthase (also called glycine cleavage enzyme). This conversion is readily reversible:[36]

CO2 + NH+
4
+ N5,N10-methylene tetrahydrofolate + NADH + H+ ⇌ Glycine + tetrahydrofolate + NAD+

In addition to being synthesized from serine, glycine can also be derived from threonine, choline or hydroxyproline via inter-organ metabolism of the liver and kidneys.[38]

Degradation

edit

Glycine is degraded via three pathways. The predominant pathway in animals and plants is the reverse of the glycine synthase pathway mentioned above. In this context, the enzyme system involved is usually called the glycine cleavage system:[36]

Glycine + tetrahydrofolate + NAD+ ⇌ CO2 + NH+
4
+ 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.[36]

In the third pathway of its 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.[36]

The half-life of glycine and its elimination from the body varies significantly based on dose.[39] In one study, the half-life varied between 0.5 and 4.0 hours.[39]

Physiological function

edit

The principal function of glycine is it acts as a precursor to proteins. Most proteins incorporate only small quantities of glycine, a notable exception being collagen, which contains about 35% glycine due to its periodically repeated role in the formation of collagen's helix structure in conjunction with hydroxyproline.[36][40] In the genetic code, glycine is coded by all codons starting with GG, namely GGU, GGC, GGA and GGG.[8]

As a biosynthetic intermediate

edit

In higher eukaryotes, δ-aminolevulinic acid, the key precursor to porphyrins, is biosynthesized from glycine and succinyl-CoA by the enzyme ALA synthase. Glycine provides the central C2N subunit of all purines.[36]

As a neurotransmitter

edit

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) glutamatergic receptors which are excitatory.[41] The LD50 of glycine is 7930 mg/kg in rats (oral),[42] and it usually causes death by hyperexcitability.

As a toxin conjugation agent

edit

Glycine conjugation pathway has not been fully investigated.[43] Glycine is thought to be a hepatic detoxifier of a number endogenous and xenobiotic organic acids.[44] Bile acids are normally conjugated to glycine in order to increase their solubility in water.[45]

The human body rapidly clears sodium benzoate by combining it with glycine to form hippuric acid which is then excreted.[46] The metabolic pathway for this begins with the conversion of benzoate by butyrate-CoA ligase into an intermediate product, benzoyl-CoA,[47] which is then metabolized by glycine N-acyltransferase into hippuric acid.[48]

Uses

edit

In the US, glycine is typically sold in two grades: United States Pharmacopeia ("USP"), and technical grade. USP grade sales account for approximately 80 to 85 percent of the U.S. market for glycine. If purity greater than the USP standard is needed, for example for intravenous injections, a more expensive pharmaceutical grade glycine can be used. Technical grade glycine, which may or may not meet USP grade standards, is sold at a lower price for use in industrial applications, e.g., as an agent in metal complexing and finishing.[49]

Animal and human foods

edit
 
Structure of cis-Cu(glycinate)2(H2O)[50]

Glycine is not widely used in foods for its nutritional value, except in infusions. Instead, glycine's role in food chemistry is as a flavorant. It is mildly sweet, and it counters the aftertaste of saccharine. It also has preservative properties, perhaps owing to its complexation to metal ions. Metal glycinate complexes, e.g. copper(II) glycinate are used as supplements for animal feeds.[27]

As of 1971, the U.S. Food and Drug Administration "no longer regards glycine and its salts as generally recognized as safe for use in human food",[51] and only permits food uses of glycine in certain conditions.[52]

Glycine has been researched for its potential to extend life.[53][54] The proposed mechanisms of this effect are its ability to clear methionine from the body, and activating autophagy.[53]

Chemical feedstock

edit

Glycine is an intermediate in the synthesis of a variety of chemical products. It is used in the manufacture of the herbicides glyphosate,[55] iprodione, glyphosine, imiprothrin, and eglinazine.[27] It is used as an intermediate of antibiotics such as thiamphenicol.[citation needed]

Laboratory research

edit

Glycine is a significant component of some solutions used in the SDS-PAGE method of protein analysis. It serves as a buffering agent, maintaining pH and preventing sample damage during electrophoresis.[56] Glycine is also used to remove protein-labeling antibodies from Western blot membranes to enable the probing of numerous proteins of interest from SDS-PAGE gel. This allows more data to be drawn from the same specimen, increasing the reliability of the data, reducing the amount of sample processing, and number of samples required.[57] This process is known as stripping.

Presence in space

edit

The presence of glycine outside the Earth was confirmed in 2009, based on the analysis of samples that had been taken in 2004 by the NASA spacecraft Stardust from comet Wild 2 and subsequently returned to Earth. Glycine had previously been identified in the Murchison meteorite in 1970.[58] The discovery of glycine in outer space bolstered the hypothesis of so-called soft-panspermia, which claims that the "building blocks" of life are widespread throughout the universe.[59] In 2016, detection of glycine within Comet 67P/Churyumov–Gerasimenko by the Rosetta spacecraft was announced.[60]

The detection of glycine outside the Solar System in the interstellar medium has been debated.[61]

Evolution

edit

Glycine is proposed to be defined by early genetic codes.[62][63][64][65] For example, low complexity regions (in proteins), that may resemble the proto-peptides of the early genetic code are highly enriched in glycine.[65]

Presence in foods

edit
Food sources of glycine[66]
Food Percentage
content
by weight
(g/100g)
Snacks, pork skins 11.04
Sesame seeds flour (low fat) 3.43
Beverages, protein powder (soy-based) 2.37
Seeds, safflower seed meal, partially defatted 2.22
Meat, bison, beef and others (various parts) 1.5–2.0
Gelatin desserts 1.96
Seeds, pumpkin and squash seed kernels 1.82
Turkey, all classes, back, meat and skin 1.79
Chicken, broilers or fryers, meat and skin 1.74
Pork, ground, 96% lean / 4% fat, cooked, crumbles 1.71
Bacon and beef sticks 1.64
Peanuts 1.63
Crustaceans, spiny lobster 1.59
Spices, mustard seed, ground 1.59
Salami 1.55
Nuts, butternuts, dried 1.51
Fish, salmon, pink, canned, drained solids 1.42
Almonds 1.42
Fish, mackerel 0.93
Cereals ready-to-eat, granola, homemade 0.81
Leeks, (bulb and lower-leaf portion), freeze-dried 0.7
Cheese, parmesan (and others), grated 0.56
Soybeans, green, cooked, boiled, drained, without salt 0.51
Bread, protein (includes gluten) 0.47
Egg, whole, cooked, fried 0.47
Beans, white, mature seeds, cooked, boiled, with salt 0.38
Lentils, mature seeds, cooked, boiled, with salt 0.37

See also

edit

References

edit
  1. ^ The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (11th ed.), Merck, 1989, ISBN 091191028X, 4386
  2. ^ "Glycine". PubChem.
  3. ^ Handbook of Chemistry and Physics, CRC Press, 59th edition, 1978.[page needed]
  4. ^ "Solubilities and densities". Prowl.rockefeller.edu. Archived from the original on September 12, 2017. Retrieved November 13, 2013.
  5. ^ Dawson, R.M.C., et al., Data for Biochemical Research, Oxford, Clarendon Press, 1959.[page needed]
  6. ^ "Nomenclature and Symbolism for Amino Acids and Peptides". IUPAC-IUB Joint Commission on Biochemical Nomenclature. 1983. Archived from the original on October 9, 2008. Retrieved March 5, 2018.
  7. ^ "Glycine | Definition of glycine in English by Oxford Dictionaries". Archived from the original on January 29, 2018.
  8. ^ a b Pawlak K, Błażej P, Mackiewicz D, Mackiewicz P (January 2023). "The Influence of the Selection at the Amino Acid Level on Synonymous Codon Usage from the Viewpoint of Alternative Genetic Codes". International Journal of Molecular Sciences. 24 (2): 1185. doi:10.3390/ijms24021185. PMC 9866869. PMID 36674703.
  9. ^ Zafra F, Aragón C, Giménez C (June 1997). "Molecular biology of glycinergic neurotransmission". Molecular Neurobiology. 14 (3): 117–142. doi:10.1007/BF02740653. PMID 9294860.
  10. ^ Atchison W (2018). "Toxicology of the Neuromuscular Junction". Comprehensive Toxicology. pp. 259–282. doi:10.1016/B978-0-12-801238-3.99198-0. ISBN 978-0-08-100601-6.
  11. ^ Matsumoto A, Ozaki H, Tsuchiya S, Asahi T, Lahav M, Kawasaki T, et al. (April 2019). "Achiral amino acid glycine acts as an origin of homochirality in asymmetric autocatalysis". Organic & Biomolecular Chemistry. 17 (17): 4200–4203. doi:10.1039/C9OB00345B. PMID 30932119.
  12. ^ Alves A, Bassot A, Bulteau AL, Pirola L, Morio B (June 2019). "Glycine Metabolism and Its Alterations in Obesity and Metabolic Diseases". Nutrients. 11 (6): 1356. doi:10.3390/nu11061356. PMC 6627940. PMID 31208147.
  13. ^ Plimmer RH (1912) [1908]. Plimmer RH, Hopkins F (eds.). The chemical composition of the proteins. Monographs on biochemistry. Vol. Part I. Analysis (2nd ed.). London: Longmans, Green and Co. p. 82. Retrieved January 18, 2010.
  14. ^ Braconnot H (1820). "Sur la conversion des matières animales en nouvelles substances par le moyen de l'acide sulfurique" [On the conversion of animal materials into new substances by means of sulfuric acid]. Annales de Chimie et de Physique. 2nd series (in French). 13: 113–125. ; see p. 114.
  15. ^ MacKenzie C (1822). One Thousand Experiments in Chemistry: With Illustrations of Natural Phenomena; and Practical Observations on the Manufacturing and Chemical Processes at Present Pursued in the Successful Cultivation of the Useful Arts …. Sir R. Phillips and Company. p. 557.
  16. ^ Boussingault (1838). "Sur la composition du sucre de gélatine et de l'acide nitro-saccharique de Braconnot" [On the composition of sugar of gelatine and of nitro-glucaric acid of Braconnot]. Comptes Rendus (in French). 7: 493–495.
  17. ^ Horsford EN (1847). "Glycocoll (gelatine sugar) and some of its products of decomposition". The American Journal of Science and Arts. 2nd series. 3: 369–381.
  18. ^ Ihde AJ (1984). The Development of Modern Chemistry. Courier Corporation. p. 167. ISBN 978-0-486-64235-2.
  19. ^ Berzelius J (1848). Jahres-Bericht über die Fortschritte der Chemie und Mineralogie (Annual Report on the Progress of Chemistry and Mineralogy). Vol. 47. Tübigen, (Germany): Laupp. p. 654. From p. 654: "Er hat dem Leimzucker als Basis den Namen Glycocoll gegeben. … Glycin genannt werden, und diesen Namen werde ich anwenden." (He [i.e., the American scientist Eben Norton Horsford, then a student of the German chemist Justus von Liebig] gave the name "glycocoll" to Leimzucker [sugar of gelatine], a base. This name is not euphonious and has besides the flaw that it clashes with the names of the rest of the bases. It is compounded from γλυχυς (sweet) and χολλα (animal glue). Since this organic base is the only [one] which tastes sweet, then it can much more briefly be named "glycine", and I will use this name.)
  20. ^ Nye MJ (1999). Before Big Science: The Pursuit of Modern Chemistry and Physics, 1800-1940. Harvard University Press. p. 141. ISBN 978-0-674-06382-2.
  21. ^ "glycine". Oxford Dictionaries. Archived from the original on November 13, 2014. Retrieved December 6, 2015.
  22. ^ Cahours A (1858). "Recherches sur les acides amidés" [Investigations into aminated acids]. Comptes Rendus (in French). 46: 1044–1047.
  23. ^ Okafor N (2016). Modern Industrial Microbiology and Biotechnology. CRC Press. p. 385. ISBN 978-1-4398-4323-9.
  24. ^ Ingersoll AW, Babcock SH (1932). "Hippuric acid". Organic Syntheses. 12: 40; Collected Volumes, vol. 2, p. 328.
  25. ^ Kirk-Othmer Food and Feed Technology, 2 Volume Set. John Wiley & Sons. 2007. p. 38. ISBN 978-0-470-17448-7.
  26. ^ "Glycine Conference (prelim)". USITC. Archived from the original on February 22, 2012. Retrieved June 13, 2014.{{cite web}}: CS1 maint: bot: original URL status unknown (link)
  27. ^ a b c Drauz K, Grayson I, Kleemann A, Krimmer HP, Leuchtenberger W, Weckbecker C (2007). "Amino Acids". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a02_057.pub2. ISBN 978-3-527-30385-4.
  28. ^ Hart JR (2005). "Ethylenediaminetetraacetic Acid and Related Chelating Agents". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a10_095. ISBN 978-3527306732.
  29. ^ Tomiyasu H, Gordon G (April 1976). "Ring closure in the reaction of metal chelates. Formation of the bidentate oxovanadium(IV)-glycine complex". Inorganic Chemistry. 15 (4): 870–874. doi:10.1021/ic50158a027.
  30. ^ Lutz OM, Messner CB, Hofer TS, Glätzle M, Huck CW, Bonn GK, et al. (May 2013). "Combined Ab Initio Computational and Infrared Spectroscopic Study of the cis- and trans-Bis(glycinato)copper(II) Complexes in Aqueous Environment". The Journal of Physical Chemistry Letters. 4 (9): 1502–1506. doi:10.1021/jz400288c. PMID 26282305.
  31. ^ D'Angelo P, Bottari E, Festa MR, Nolting HF, Pavel NV (April 1998). "X-ray Absorption Study of Copper(II)−Glycinate Complexes in Aqueous Solution". The Journal of Physical Chemistry B. 102 (17): 3114–3122. doi:10.1021/jp973476m.
  32. ^ Ingersoll AW, Babcock SH (1932). "Hippuric Acid". Org. Synth. 12: 40. doi:10.15227/orgsyn.012.0040.
  33. ^ Herbst RM, Shemin D (1939). "Acetylglycine". Org. Synth. 19: 4. doi:10.15227/orgsyn.019.0004.
  34. ^ Van Dornshuld E, Vergenz RA, Tschumper GS (July 2014). "Peptide bond formation via glycine condensation in the gas phase". The Journal of Physical Chemistry B. 118 (29): 8583–8590. doi:10.1021/jp504924c. PMID 24992687.
  35. ^ Leng L, Yang L, Zu H, Yang J, Ai Z, Zhang W, et al. (November 2023). "Insights into glycine pyrolysis mechanisms: Integrated experimental and molecular dynamics/DFT simulation studies". Fuel. 351: 128949. Bibcode:2023Fuel..35128949L. doi:10.1016/j.fuel.2023.128949.
  36. ^ a b c d e f g Nelson DL, Cox MM (2005). Principles of Biochemistry (4th ed.). New York: W. H. Freeman. pp. 127, 675–77, 844, 854. ISBN 0-7167-4339-6.
  37. ^ Kwon YK, Higgins MB, Rabinowitz JD (August 2010). "Antifolate-induced depletion of intracellular glycine and purines inhibits thymineless death in E. coli". ACS Chemical Biology. 5 (8): 787–795. doi:10.1021/cb100096f. PMC 2945287. PMID 20553049.
  38. ^ Wang W, Wu Z, Dai Z, Yang Y, Wang J, Wu G (September 2013). "Glycine metabolism in animals and humans: implications for nutrition and health". Amino Acids. 45 (3): 463–477. doi:10.1007/s00726-013-1493-1. PMID 23615880. S2CID 7577607.
  39. ^ a b Hahn RG (1993). "Dose-dependent half-life of glycine". Urological Research. 21 (4): 289–291. doi:10.1007/BF00307714. PMID 8212419. S2CID 25138444.
  40. ^ Szpak P (2011). "Fish bone chemistry and ultrastructure: implications for taphonomy and stable isotope analysis". Journal of Archaeological Science. 38 (12): 3358–3372. Bibcode:2011JArSc..38.3358S. doi:10.1016/j.jas.2011.07.022.
  41. ^ Liu Y, Zhang J (October 2000). "Recent development in NMDA receptors". Chinese Medical Journal. 113 (10): 948–56. PMID 11775847.
  42. ^ "Safety (MSDS) data for glycine". The Physical and Theoretical Chemistry Laboratory Oxford University. 2005. Archived from the original on October 20, 2007. Retrieved November 1, 2006.
  43. ^ van der Sluis R, Badenhorst CP, Erasmus E, van Dyk E, van der Westhuizen FH, van Dijk AA (October 2015). "Conservation of the coding regions of the glycine N-acyltransferase gene further suggests that glycine conjugation is an essential detoxification pathway". Gene. 571 (1): 126–134. doi:10.1016/j.gene.2015.06.081. PMID 26149650.
  44. ^ Badenhorst CP, Erasmus E, van der Sluis R, Nortje C, van Dijk AA (August 2014). "A new perspective on the importance of glycine conjugation in the metabolism of aromatic acids". Drug Metabolism Reviews. 46 (3): 343–361. doi:10.3109/03602532.2014.908903. PMID 24754494.
  45. ^ Di Ciaula A, Garruti G, Lunardi Baccetto R, Molina-Molina E, Bonfrate L, Wang DQ, et al. (November 2017). "Bile Acid Physiology". Annals of Hepatology. 16 (Suppl. 1: s3-105): s4–s14. doi:10.5604/01.3001.0010.5493. hdl:11586/203563. PMID 29080336.
  46. ^ Nair B (January 2001). "Final report on the safety assessment of Benzyl Alcohol, Benzoic Acid, and Sodium Benzoate". International Journal of Toxicology. 20 Suppl 3 (3_suppl): 23–50. doi:10.1080/10915810152630729. PMID 11766131.
  47. ^ "butyrate-CoA ligase". BRENDA. Technische Universität Braunschweig. Retrieved May 7, 2014. Substrate/Product
  48. ^ "glycine N-acyltransferase". BRENDA. Technische Universität Braunschweig. Retrieved May 7, 2014. Substrate/Product
  49. ^ "Glycine From Japan and Korea" (PDF). U.S. International Trade Commission. January 2008. Archived (PDF) from the original on June 6, 2010. Retrieved June 13, 2014.
  50. ^ Casari BM, Mahmoudkhani AH, Langer V (2004). "A Redetermination of cis-Aquabis(glycinato-κ2N,O)copper(II)". Acta Crystallogr. E. 60 (12): m1949–m1951. doi:10.1107/S1600536804030041.
  51. ^ "eCFR :: 21 CFR 170.50 -- Glycine (aminoacetic acid) in food for human consumption". ecfr.gov. Retrieved October 24, 2022.
  52. ^ "eCFR :: 21 CFR 172.812 -- Glycine". ecfr.gov. Retrieved July 6, 2024.
  53. ^ a b Johnson AA, Cuellar TL (June 2023). "Glycine and aging: Evidence and mechanisms". Ageing Research Reviews. 87: 101922. doi:10.1016/j.arr.2023.101922. PMID 37004845.
  54. ^ Soh J, Raventhiran S, Lee JH, Lim ZX, Goh J, Kennedy BK, et al. (February 2024). "The effect of glycine administration on the characteristics of physiological systems in human adults: A systematic review". GeroScience. 46 (1): 219–239. doi:10.1007/s11357-023-00970-8. PMC 10828290. PMID 37851316.
  55. ^ Stahl SS, Alsters PL (2016). Liquid Phase Aerobic Oxidation Catalysis: Industrial Applications and Academic Perspectives. John Wiley & Sons. p. 268. ISBN 978-3-527-69015-2.
  56. ^ Schägger H (May 12, 2006). "Tricine-SDS-PAGE". Nature Protocols. 1 (1): 16–22. doi:10.1038/nprot.2006.4. PMID 17406207.
  57. ^ Legocki RP, Verma DP (March 1981). "Multiple immunoreplica Technique: screening for specific proteins with a series of different antibodies using one polyacrylamide gel". Analytical Biochemistry. 111 (2): 385–392. doi:10.1016/0003-2697(81)90577-7. PMID 6166216.
  58. ^ Kvenvolden K, Lawless J, Pering K, Peterson E, Flores J, Ponnamperuma C, et al. (December 1970). "Evidence for extraterrestrial amino-acids and hydrocarbons in the Murchison meteorite". Nature. 228 (5275): 923–926. Bibcode:1970Natur.228..923K. doi:10.1038/228923a0. PMID 5482102. S2CID 4147981.
  59. ^ "Building block of life found on comet - Thomson Reuters 2009". Reuters. August 18, 2009. Retrieved August 18, 2009.
  60. ^ European Space Agency (May 27, 2016). "Rosetta's comet contains ingredients for life". Retrieved June 5, 2016.
  61. ^ Ramos MF, Silva NA, Muga NJ, Pinto AN (February 2020). "Reversal operator to compensate polarization random drifts in quantum communications". Optics Express. 28 (4): 5035–5049. arXiv:astro-ph/0410335. Bibcode:2005ApJ...619..914S. doi:10.1086/426677. PMID 32121732. S2CID 16286204.
  62. ^ Trifonov EN (December 2000). "Consensus temporal order of amino acids and evolution of the triplet code". Gene. 261 (1): 139–151. doi:10.1016/S0378-1119(00)00476-5. PMID 11164045.
  63. ^ Higgs PG, Pudritz RE (June 2009). "A thermodynamic basis for prebiotic amino acid synthesis and the nature of the first genetic code". Astrobiology. 9 (5): 483–490. arXiv:0904.0402. Bibcode:2009AsBio...9..483H. doi:10.1089/ast.2008.0280. PMID 19566427. S2CID 9039622.
  64. ^ Chaliotis A, Vlastaridis P, Mossialos D, Ibba M, Becker HD, Stathopoulos C, et al. (February 2017). "The complex evolutionary history of aminoacyl-tRNA synthetases". Nucleic Acids Research. 45 (3): 1059–1068. doi:10.1093/nar/gkw1182. PMC 5388404. PMID 28180287.
  65. ^ a b Ntountoumi C, Vlastaridis P, Mossialos D, Stathopoulos C, Iliopoulos I, Promponas V, et al. (November 2019). "Low complexity regions in the proteins of prokaryotes perform important functional roles and are highly conserved". Nucleic Acids Research. 47 (19): 9998–10009. doi:10.1093/nar/gkz730. PMC 6821194. PMID 31504783.
  66. ^ "FoodData Central Search Results for "Glycine (g)"". fdc.nal.usda.gov. Retrieved May 26, 2024.

Further reading

edit
edit