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Encyclopedia > Tryptophan
3D stick model of tryptophan molecule

Tryptophan Image File history File links L-Tryptophan. ... Image File history File links Download high resolution version (712x821, 27 KB) Licensing File links The following pages link to this file: Tryptophan ...

Systematic (IUPAC) name
(S)-2-Amino-3-(1H-indol-3-yl)-propionic acid
Identifiers
CAS number 73-22-3
PubChem         6305
Chemical data
Formula C11H12N2O2 
Molar mass 204.225 g/mol
SMILES N[C@@H](Cc1c2ccccc2n([H])c1)C(O)=O
Complete data

Tryptophan (abbreviated as Trp or W)[1] is one of the 20 standard amino acids, which are the building blocks of proteins, and an essential amino acid in the human diet. It is encoded by the genetic code (as codon UGG). Only the L-stereoisomer of tryptophan is used in structural or enzyme proteins, but the D-stereoisomer is occasionally found in naturally produced peptides (for example, the marine venom peptide contryphan).[2] The distinguishing structural characteristic of tryptophan is that it contains an indole functional group. IUPAC nomenclature is a systematic way of naming organic chemical compounds. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences and alloys. ... PubChem is a database of chemical molecules. ... A chemical formula is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... For other uses, see Carbon (disambiguation). ... This article is about the chemistry of hydrogen. ... General Name, symbol, number nitrogen, N, 7 Chemical series nonmetals Group, period, block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... General Name, symbol, number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, period, block 16, 2, p Appearance colorless (gas) pale blue (liquid) Standard atomic weight 15. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ... Physical properties Hazard properties Chemical properties Pharmacological properties OrganicBox_complete a  73-22-3 EINECS for Tryptophan a  PubChem 9060 a  PubChem 6305 Category: ... It has been suggested that this article or section be merged with Proteinogenic amino acid. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... 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. ... This article is about modern humans. ... For a non-technical introduction to the topic, see Introduction to Genetics. ... RNA codons. ... Stereoisomerism is the arrangement of atoms in molecules whose connectivity remains the same but their arrangement in space is different in each isomer. ... Fibrous proteins, also called scleroproteins, are long filamentous protein molecules that form one of the two main classes of tertiary structure protein (the other being globular proteins). ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... Stereoisomerism is the arrangement of atoms in molecules whose connectivity remains the same but their arrangement in space is different in each isomer. ... Peptides (from the Greek πεπτος, digestible), are the family of short molecules formed from the linking, in a defined order, of various α-amino acids. ... Peptides (from the Greek πεπτος, digestible), are the family of short molecules formed from the linking, in a defined order, of various α-amino acids. ... Conus textile, which produces contryphans The contryphans (conus + tryptophan) are a family of peptides (InterPro IPR011062, SCOP 58505) which are active constituents of venom produced by cone snail (genus conus). ... Indole is an aromatic heterocyclic organic compound. ...

Contents

Isolation

The isolation of tryptophan was first reported by Sir Frederick Hopkins in 1901.[3] It has been obtained by hydrolysis of casein. From 600 g of crude casein one obtains 4-8 grams of tryptophan.[4] Sir Frederick Gowland Hopkins (June 20, 1861 – May 16, 1947) was an English biochemist, he was awarded the Nobel Prize in Physiology or Medicine in 1929 with Christiaan Eijkman for the discovery of vitamins. ... Casein (from Latin caseus cheese) is the most predominant phosphoprotein found in milk and cheese. ...


Biosynthesis and industrial production

Plants and microorganisms commonly synthesize tryptophan from shikimic acid or anthranilate.[5] The latter condenses with phosphoribosylpyrophosphate (PRPP), generating pyrophosphate as a by-product. After ring opening of the ribose moiety and following reductive decarboxylation, indole-3-glycerinephosphate is produced, which in turn is transformed into indole. In the last step, tryptophan synthethase catalyzes the formation of tryptophan from indole and the amino acid, serine. A cluster of Escherichia coli bacteria magnified 10,000 times. ... Shikimic acid, more commonly known as its anionic form shikimate, is an important biochemical intermediate in plants and microorganisms. ... Anthranilic acid has the formula C7H7NO2[1] and is an odorless white to yellow crystalline acid, which is freely soluble in water. ... Phosphoribosyl pyrophosphate (PRPP) is a pentosephosphate. ... In chemistry, the anion, the salts, and the esters of pyrophosphoric acid are called pyrophosphates. ... Indole is an aromatic heterocyclic organic compound. ... Serine (IPA ), organic compound, one of the 20 amino acids commonly found in animal proteins. ...

The industrial production of tryptophan is also biosynthetic and is based on the fermentation of serine and indole using either wild-type or genetically modified E. coli. The conversion is catalyzed by the enzyme tryptophan synthase.[6] Image File history File links Size of this preview: 800 × 270 pixelsFull resolution‎ (3,599 × 1,214 pixels, file size: 269 KB, MIME type: image/png) Created myself using ChemDraw based on Yikrazuuls Image:Tryptophanesynthesis. ... See also Entamoeba coli. ... Tryptophan synthase (EC 4. ...


Function

Metabolism of L-tryptophan into serotonin and melatonin (left) and niacin (right). Transformed functional groups after each chemical reaction are highlighted in red.
Metabolism of L-tryptophan into serotonin and melatonin (left) and niacin (right). Transformed functional groups after each chemical reaction are highlighted in red.

For many organisms including humans, tryptophan is an essential amino acid. This means that it cannot be synthesized by the organism and therefore must be part of its diet. The principal function of amino acids including tryptophan are as building blocks in protein biosynthesis. In addition, tryptophan functions as a biochemical precursor for the following compounds (see also figure to the right): Image File history File links Size of this preview: 385 × 599 pixelsFull resolution (2782 × 4325 pixel, file size: 611 KB, MIME type: image/png) Created myself using ChemDraw I, the copyright holder of this work, hereby release it into the public domain. ... Image File history File links Size of this preview: 385 × 599 pixelsFull resolution (2782 × 4325 pixel, file size: 611 KB, MIME type: image/png) Created myself using ChemDraw I, the copyright holder of this work, hereby release it into the public domain. ... 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. ... Protein biosynthesis (synthesis) is the process in which cells build proteins. ... In chemistry a precursor is a compound that participates in the chemical reaction that produces another compound. ...

In bacteria that synthesize tryptophan, high cellular levels of this amino acid activate a repressor protein, which binds to the trp operon. [citation needed] Binding of this repressor to the tryptophan operon prevents transcription of downstream DNA that codes for the enzymes involved in the biosynthesis of tryptophan. So high levels of tryptophan prevent tryptophan synthesis through a negative feedback loop and, when the cell's tryptophan levels are reduced, transcription from the trp operon resumes. The genetic organization of the trp operon thus permits tightly regulated and rapid responses to changes in the cell's internal and external tryptophan levels. Serotonin (pronounced ) (5-hydroxytryptamine, or 5-HT) is a monoamine neurotransmitter synthesized in serotonergic neurons in the central nervous system (CNS) and enterochromaffin cells in the gastrointestinal tract of animals including humans. ... Chemical structure of D-aspartic acid, a common amino acid neurotransmitter. ... Tryptophan hydroxylase (TPH) is an enzyme (EC 1. ... Melatonin, 5-methoxy-N-acetyltryptamine, is a hormone found in all living creatures from algae[1] to humans, at levels that vary in a diurnal cycle. ... A neurohormone is any hormone produced by neurosecretory cells, usually in the brain. ... Wikipedia does not have an article with this exact name. ... 5-hydroxyindole-O-methyltransferase is a gene involved in the conversion of serotonin to melatonin in pinealocytes. ... Niacin, also known as nicotinic acid or vitamin B3, is a water-soluble vitamin whose derivatives such as NADH, NAD, NAD+, and NADP play essential roles in energy metabolism in the living cell and DNA repair. ... Kynurenine is a metabolite of the amino acid tryptophan used in the production of niacin. ... A repressor is a DNA-binding protein that regulates the expression of one or more genes by decreasing the rate of transcription. ... Trp operon is an anabolic operon which promotes the production of tryptophan in the absence of tryptophan in the environment. ...


Dietary sources

Tryptophan as a component of dietary protein is particularly plentiful in chocolate, oats, bananas, mangoes, dried dates, milk, yogurt, cottage cheese, red meat, eggs, fish, poultry, sesame, chickpeas, sunflower seeds, pumpkin seeds, spirulina, and peanuts. [11] It is also found in turkey at a level typical of poultry in general.[12] For other uses, see Chocolate (disambiguation). ... Binomial name Avena sativa Carolus Linnaeus (1753) The Oat (Avena sativa) is a species of cereal grain, and the seeds of this plant. ... This article or section does not cite its references or sources. ... Species About 35 species, including: Mangifera altissima Mangifera applanata Mangifera caesia Mangifera camptosperma Mangifera casturi Mangifera decandra Mangifera foetida Mangifera gedebe Mangifera griffithii Mangifera indica Mangifera kemanga Mangifera laurina Mangifera longipes Mangifera macrocarpa Mangifera mekongensis Mangifera odorata Mangifera pajang Mangifera pentandra Mangifera persiciformis Mangifera quadrifida Mangifera siamensis Mangifera similis Mangifera... Binomial name L. The Date Palm (Phoenix dactylifera) is a palm in the genus Phoenix, extensively cultivated for its edible fruit. ... A glass of cows milk. ... Yoghurt Yoghurt or yogurt, less commonly yoghourt or yogourt, is a dairy product produced by bacterial fermentation of milk. ... A tub of cottage cheese Cottage cheese comes from chickens and is a cheese curd product with a mild flavor. ... Red meat in culinary terminology refers to meat which is red-colored when raw, while in nutritional terminology, it refers to meat from mammals. ... An egg is a body consisting of an ovum surrounded by layers of membranes and an outer casing of some type, which acts to nourish and protect a developing embryo. ... For other uses, see Fish (disambiguation). ... This article does not cite any references or sources. ... Binomial name Sesamum indicum L. Sesame (Sesamum indicum) is a flowering plant in the genus Sesamum. ... Binomial name Cicer arietinum L. Percentages are relative to US recommendations for adults. ... The sunflower seed is the seed of the sunflower (Helianthus annuus). ... Pumpkins Pumpkin attached to a stalk A pumpkin is a squash vegetable, most commonly orange in colour when ripe, that grows as a fruit (gourd from a trailing vine of the genus Cucurbita (Cucurbitaceae). ... Spirulina may refer to: Spirulina (dietary supplement), a popular health-food supplement made from the Arthrospira genus of cyanobacteria. ... Binomial name L. This article is about the legume. ...

Tryptophan (Trp) Content of Various Foods[12][13]
Food
Protein
[g/100 g of food]
Tryptophan
[g/100 g of food]
Tryptophan/Protein [%]
turkey
21.89
0.24
1.11
cheese, cheddar
24.90
0.32
1.29
chicken
20.85
0.24
1.14
beef
20.13
0.23
1.12
lamb, chop
18.33
0.21
1.17
pork, chop
19.27
0.25
1.27
salmon
19.84
0.22
1.12
perch, Atlantic
18.62
0.21
1.12
milk
3.22
0.08
2.34
egg
12.58
0.17
1.33
wheat flour, white
10.33
0.13
1.23
potatoes, russet
2.14
0.02
0.84
rice, white
7.13
0.08
1.16

Use as a dietary supplement

For some time, tryptophan was available in health food stores as a dietary supplement. Many people found tryptophan to be a safe and reasonably effective sleep aid, probably due to its ability to increase brain levels of serotonin (a calming neurotransmitter when present in moderate levels)[14] and/or melatonin (a sleep-inducing hormone secreted by the pineal gland in response to darkness or low light levels).[15][16] A dietary supplement is intended to supply nutrients, (vitamins, minerals, fatty acids or amino acids) that are missing or not consumed in sufficient quantity in a persons diet. ... The human brain In animals, the brain (enkephalos) (Greek for in the skull), is the control center of the central nervous system, responsible for behavior. ... Serotonin (pronounced ) (5-hydroxytryptamine, or 5-HT) is a monoamine neurotransmitter synthesized in serotonergic neurons in the central nervous system (CNS) and enterochromaffin cells in the gastrointestinal tract of animals including humans. ... Chemical structure of D-aspartic acid, a common amino acid neurotransmitter. ... Melatonin, 5-methoxy-N-acetyltryptamine, is a hormone found in all living creatures from algae[1] to humans, at levels that vary in a diurnal cycle. ... For other uses, see Hormone (disambiguation). ... The pineal gland (also called the pineal body or epiphysis) is a small endocrine gland in the brain. ...


Clinical research tended to confirm tryptophan's effectiveness as a sleep aid[17][18][19] and for a growing variety of other conditions typically associated with low serotonin levels or activity in the brain[20] such as premenstrual dysphoric disorder [21] and seasonal affective disorder.[22][23] In particular, tryptophan showed considerable promise as an antidepressant alone,[24] and as an "augmenter" of antidepressant drugs.[24][25] However others have questioned the reliability of these clinical trials.[26][27] Premenstrual dysphoric disorder (PMDD) is a severe form of premenstrual syndrome, afflicting 8% of all women. ... Seasonal affective disorder, or SAD, also known as winter depression or winter blues is an affective, or mood, disorder. ... Prozac, a selective serotonin reuptake inhibitor (SSRI) Serotonin-norepinephrine reuptake inhibitor, Venlafaxine An antidepressant, is a psychiatric medication or other substance (nutrient or herb) used for alleviating depression or dysthymia (milder depression). ... Prozac, a selective serotonin reuptake inhibitor (SSRI) Serotonin-norepinephrine reuptake inhibitor, Venlafaxine An antidepressant, is a psychiatric medication or other substance (nutrient or herb) used for alleviating depression or dysthymia (milder depression). ...


Metabolites

5-Hydroxytryptophan (5-HTP), a metabolite of tryptophan, has been suggested as a treatment for epilepsy[28] and depression, although clinical trials are inconclusive and lacking.[29] 5-Hydroxytryptophan or 5-HTP is a naturally-occurring amino acid, a precursor to the neurotransmitter serotonin and an intermediate in tryptophan metabolism. ...


5-HTP readily crosses the blood-brain barrier and in addition is rapidly decarboxylated to serotonin (5-hydroxytryptamine or 5-HT)[30] and therefore may be useful for the treatment of depression. However serotonin has a relatively short half-life since it is rapidly metabolized by monoamine oxidase, and therefore is likely to have limited efficacy. It is marketed in Europe for depression and other indications under the brand names Cincofarm and Tript-OH. Serotonin (pronounced ) (5-hydroxytryptamine, or 5-HT) is a monoamine neurotransmitter synthesized in serotonergic neurons in the central nervous system (CNS) and enterochromaffin cells in the gastrointestinal tract of animals including humans. ... Monoamine oxidase Monoamine oxidases (singular abbreviation MAO) (EC 1. ...


In the United States, 5-HTP does not require a prescription, as it is covered under the Dietary Supplement Act. However, since the quality of dietary supplements is not regulated by the FDA, the quality of dietary and nutritional supplements tends to vary, and there is no guarantee that the label accurately depicts what the bottle contains. A prescribed dietary supplement supplies nutrients (usually vitamins or minerals) that are missing or not consumed in sufficient quantity in a persons diet. ... The United States Food and Drug Administration is the government agency responsible for regulating food, dietary supplements, drugs, cosmetics, medical devices, biologics and blood products in the United States. ...


Tryptophan supplements and EMS

Although currently available for purchase, in 1989 a large outbreak (1500 cases including at least 37 deaths) of a disabling autoimmune illness called eosinophilia-myalgia syndrome (EMS) was traced by some epidemiological studies[31][32][33] to L-tryptophan supplied by a Japanese manufacturer, Showa Denko KK.[34] It was further hypothesized that one or more trace impurities produced during the manufacture of tryptophan may have been responsible for the EMS outbreak.[35][36] However, many people who consumed Showa Denko L-tryptophan did not develop EMS and cases of EMS have occurred prior to and after the 1989 epidemic. Furthermore the methodology used in the initial epidemiological studies has been criticized.[37][38] An alternative explanation for the 1989 EMS outbreak is that large doses of tryptophan produce metabolites which inhibit the normal degradation of histamine and excess histamine in turn has been proposed to cause EMS.[39] Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. ... Eosinophilia-myalgia syndrome is an incurable and sometimes fatal flu-like neurological condition that was caused by contaminated L-tryptophan supplements. ... Shōwa Denkō K. K. (昭和電工) is a Japanese chemical company. ... Metabolites are the intermediates and products of metabolism. ... This article or section does not cite any references or sources. ...


Most tryptophan was banned from sale in the US in 1991, and other countries followed suit. Tryptophan from one manufacturer, of six, continued to be sold for manufacture of baby formulas. A Rutgers Law Journal article observed, "Political pressures have played a role in the FDA's decision to ban L-tryptophan as well as its desire to increase its regulatory power over dietary supplements."[40]


At the time of the ban, the FDA did not know, or did not indicate, that EMS was caused by a contaminated batch,[41][42] and yet, even when the contamination was discovered and the purification process fixed, the FDA maintained that L-tryptophan was unsafe. In February 2001, the FDA loosened the restrictions on marketing (though not on importation), but still expressed the following concern:

"Based on the scientific evidence that is available at the present time, we cannot determine with certainty that the occurrence of EMS in susceptible persons consuming L-tryptophan supplements derives from the content of L-tryptophan, an impurity contained in the L-tryptophan, or a combination of the two in association with other, as yet unknown, external factors."[34]

Since 2002, L-tryptophan has been sold in the U.S. in its original form. Several high-quality sources of L-tryptophan do exist, and are sold in many of the largest health food stores nationwide. Indeed, tryptophan has continued to be used in clinical and experimental studies employing human patients and subjects.


In recent years in the U.S., compounding pharmacies and some mail-order supplement retailers have begun selling tryptophan to the general public. Tryptophan has also remained on the market as a prescription drug (Tryptan), which some psychiatrists continue to prescribe, particularly as an augmenting agent for people who are unresponsive to antidepressant drugs.[citation needed] For other uses, see Pharmacy (disambiguation). ... For other uses, see Psychiatrist (disambiguation). ...


Turkey meat and drowsiness

One widely-held belief is that heavy consumption of turkey meat (as for example in a Thanksgiving feast) results in drowsiness, which has been attributed to high levels of tryptophan contained in turkey.[43][44][45] While turkey does contain high levels of tryptophan, the amount is comparable to that contained in most other meats.[12] Furthermore, postprandial Thanksgiving sedation may have more to do with what is consumed along with the turkey, in particular carbohydrates, rather than the turkey itself. The art of diplomacy, painted by Jean Leon Gerome Ferris (1863-1930). ... Look up Postprandial in Wiktionary, the free dictionary. ... Sedation is a medical procedure involving administration of sedative drugs, generally to facilitate a medical procedure, such as endoscopy, vasectomy, or minor surgery with local anaesthesia. ... Lactose is a disaccharide found in milk. ...


It has been demonstrated in both animal models[46] and in humans[47][48][49] that ingestion of a meal rich in carbohydrates triggers release of insulin. Insulin in turn stimulates the uptake of large neutral branched-chain amino acids (LNAA) but not tryptophan (trp) into muscle, increasing the ratio of trp to LNAA in the blood stream. The resulting increased ratio of tryptophan to large neutral amino acids in the blood reduces competition with other amino acids for the large neutral amino acid transporter protein for uptake of tryptophan across the blood-brain barrier into the central nervous system (CNS).[50][51] Once inside the CNS, tryptophan is converted into serotonin in the raphe nuclei by the normal enzymatic pathway.[46][48] The resultant serotonin is further metabolised into melatonin by the pineal gland.[9] Hence, these data suggest that "feast-induced drowsiness," and in particular, the common American post-Thanksgiving dinner drowsiness, may be the result of a heavy meal rich in carbohydrates which, via an indirect mechanism, increases the production of sleep-promoting serotonin and melatonin in the brain.[46][47][48][49] CD98 is a glycoprotein[1][2] which comprises the light subunit of the Large neutral Amino acid Transporter (LAT1). ... The blood-brain barrier (BBB) is a membranic structure that acts primarily to protect the brain from chemicals in the blood, while still allowing essential metabolic function. ... A diagram showing the CNS: 1. ... Serotonin (pronounced ) (5-hydroxytryptamine, or 5-HT) is a monoamine neurotransmitter synthesized in serotonergic neurons in the central nervous system (CNS) and enterochromaffin cells in the gastrointestinal tract of animals including humans. ... The raphe nuclei (Latin for the bit in a fold or seam) is a moderately sized cluster of nuclei found in the brain stem, and releases serotonin to the rest of the brain. ... Melatonin, 5-methoxy-N-acetyltryptamine, is a hormone found in all living creatures from algae[1] to humans, at levels that vary in a diurnal cycle. ... The pineal gland (also called the pineal body or epiphysis) is a small endocrine gland in the brain. ...


Fluorescence

The fluorescence of a folded protein is a mixture of the fluorescence from individual aromatic residues. Most of the intrinsic fluorescence emissions of a folded protein are due to excitation of tryptophan residues, with some emissions due to tyrosine and phenylalanine. Typically, tryptophan has a wavelength of maximum absorption of 280 nm and an emission peak that is solvatochromic, ranging from ca. 300 to 350 nm depending in the polarity of the local environment [52] Hence, protein fluorescence may be used as a diagnostic of the conformational state of a protein.[53] Furthermore, tryptophan fluorescence is strongly influenced by the proximity of other residues (i.e., nearby protonated acidic groups such as Asp or Glu can cause quenching of Trp fluorescence). Also, energy transfer between tryptophan and the other fluorescent amino acids is possible, which would affect the analysis, especially in cases where the Förster approach is taken. In addition, tryptophan is a relatively rare amino acid; many proteins contain only one or a few tryptophan residues. Therefore, tryptophan fluorescence can be a very sensitive measurement of the conformational state of individual tryptophan residues. The advantage compared to extrinsic probes is that the protein itself is not changed. The use of intrinsic fluorescence for the study of protein conformation is in practice limited to cases with few (or perhaps only one) tryptophan residues, since each experiences a different local environment, which gives rise to different emission spectra. This could be avoided by the use of time-resolved fluorescence, but would not really make the analysis much easier. Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... The Solvatochromic effect or solvatochromic shift refers to a strong dependence of absorption and emission spectra with the solvent polarity. ... Quenching refers to any process which decreases the fluorescence intensity of a given substance. ...


Fictional references

  • In James Cameron's TV series Dark Angel, genetically engineered Max Guevara and the other escaped X-5s need to take tryptophan supplements to control their seizures, which were the result of a faulty gene.
  • In the U.S. TV show an episode of Seinfeld, Jerry and George use turkey and boxed wine to cause Jerry's girlfriend to fall asleep so that they can play with her extensive antique toy collection. When Jerry's girlfriend asks what is it in turkey that makes people drowsy, Jerry and George immediately and simultaneously respond "Tryptophan"!
  • In the U.S. TV series Reno 911!, the faux-information documentary "Keeping it Real, Real Safe" claims that tryptophan is as dangerous as alcohol when it comes to driving.
  • In the episode "Psycho Therapy" of the MTV animated series Daria, Daria tells her father Jake of tryptophan in milk and its calming influences. This serves as a running gag through the episode.
  • In the U.S. TV series Titus, Christopher Titus believed it was tryptophan that caused sleepiness during a turkey dinner. It was in fact a bottle of antidepressants that his mother had put into the food.

Dark Angel is an American cyberpunk science fiction television program, created by James Cameron and Charles H. Eglee, which ran from 2000 to 2002 on the FOX network. ... The Merv Griffin Show is the sixth episode of the ninth season of Seinfeld. ... Seinfeld is an Emmy Award-winning American sitcom that originally aired on NBC from July 5, 1989 to May 14, 1998, running a total of 9 seasons. ... For the 2007 film, see Reno 911!: Miami. ... For St. ... Titus was an Emmy-nominated American dark-comedy sitcom that debuted on FOX in 2000. ...

References

  1. ^ IUPAC-IUBMB Joint Commission on Biochemical Nomenclature. Nomenclature and Symbolism for Amino Acids and Peptides. Recommendations on Organic & Biochemical Nomenclature, Symbols & Terminology etc. Retrieved on 2007-05-17.
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  6. ^ Ikeda M (2002). "Amino acid production processes". Adv. Biochem. Eng. Biotechnol. 79: 1-35. PMID 12523387. 
  7. ^ Fernstrom JD (1983). "Role of precursor availability in control of monoamine biosynthesis in brain". Physiol. Rev. 63 (2): 484-546. PMID 6132421. 
  8. ^ Schaechter JD, Wurtman RJ (1990). "Serotonin release varies with brain tryptophan levels". Brain Res. 532 (1-2): 203-10. doi:10.1016/0006-8993(90)91761-5. PMID 1704290. 
  9. ^ a b Wurtman RJ, Anton-Tay F (1969). "The mammalian pineal as a neuroendocrine transducer". Recent Prog. Horm. Res. 25: 493-522. PMID 4391290. 
  10. ^ Ikeda M, Tsuji H, Nakamura S, Ichiyama A, Nishizuka Y, Hayaishi O (1965). "Studies on the biosynthesis of nicotinamide adenine dinucleotide. II. A role of picolinic carboxylase in the biosynthesis of nicotinamide adenine dinucleotide from tryptophan in mammals". J. Biol. Chem. 240: 1395-401. PMID 14284754. 
  11. ^ Tryptophan background
  12. ^ a b c Joanne Holden, Nutrient Data Laboratory, Agricultural Research Service. USDA National Nutrient Database for Standard Reference, Release 20. United States Department of Agriculture. Retrieved on 2007-10-02.
  13. ^ Rambali B, Andel I van, Schenk E, Wolterink G, Werken G van de, Stevenson H, Vleeming W (2002). "[The contribution of cocoa additive to cigarette smoking addiction]" (PDF). RIVM (report 650270002/2002). - The National Institute for Public Health and the Environment (Netherlands)
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Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 137th day of the year (138th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 275th day of the year (276th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... ISSN, or International Standard Serial Number, is the unique eight-digit number applied to a periodical publication including electronic serials. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 224th day of the year (225th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 229th day of the year (230th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 229th day of the year (230th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 229th day of the year (230th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ...

See also

Serotonin (pronounced ) (5-hydroxytryptamine, or 5-HT) is a monoamine neurotransmitter synthesized in serotonergic neurons in the central nervous system (CNS) and enterochromaffin cells in the gastrointestinal tract of animals including humans. ... 5-HTP (5-Hydroxy-tryptophan) is decarboxylated to the neurotransmitter serotonin (5-HT) by the enzyme aromatic-L-amino-acid decarboxylase. ... Tryptamine (3-(2-aminoethyl)indole) is a monoamine compound that is widespread in nature. ...

External links


v  d  e
Major families of biochemicals
Peptides | Amino acids | Nucleic acids | Carbohydrates | Nucleotide sugars | Lipids | Terpenes | Carotenoids | Tetrapyrroles | Enzyme cofactors | Steroids | Flavonoids | Alkaloids | Polyketides | Glycosides
Analogues of nucleic acids: The 20 Common Amino Acids ("dp" = data page) Analogues of nucleic acids:
Alanine (dp) | Arginine (dp) | Asparagine (dp) | Aspartic acid (dp) | Cysteine (dp) | Glutamic acid (dp) | Glutamine (dp) | Glycine (dp) | Histidine (dp) | Isoleucine (dp) | Leucine (dp) | Lysine (dp) | Methionine (dp) | Phenylalanine (dp) | Proline (dp) | Serine (dp) | Threonine (dp) | Tryptophan (dp) | Tyrosine (dp) | Valine (dp)

  Results from FactBites:
 
Urban Legends Reference Pages: Turkey Causes Sleepiness (638 words)
Turkey does contain tryptophan, an amino acid which is a natural sedative.
But tryptophan doesn't act on the brain unless it is taken on an empty stomach with no protein present, and the amount gobbled even during a holiday feast is generally too small to have an appreciable effect.
If tryptophan were truly the sandman's henchman, we'd be falling asleep at the wheel on our way home from KFC or McDonald's.
Tryptophan (370 words)
Tryptophan is an amino acid; one of the 20 found in the basic genetic code: codon UGG.
Tryptophan is a precursor for serotonin, melatonin, and niacin.
Tryptophan is produced by the human body, but can also be found in many sources of dietary protein, including chocolate, oats, bananas, dried dates, cottage cheese, red meat, fish, milk, peanuts, and most famously turkey.
  More results at FactBites »

 
 

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