查看“︁色氨酸羟化酶”︁的源代码

{{enzyme
| Name = 色氨酸5-单加氧酶
| Systematic_name = <small>L</small>-tryptophan,tetrahydrobiopterin:oxygen oxidoreductase (5-hydroxylating)
| EC_number = 1.14.16.4
| Acronym = TPH
| Other_names = <small>L</small>-tryptophan hydroxylase; indoleacetic acid-5-hydroxylase; tryptophan 5-hydroxylase; tryptophan hydroxylase
| CAS_number = 9037-21-2
| IUBMB_EC_number = 1/14/16/4
| GO_code = 0004510
| image = 
| width = 
| caption = 
}}
{{protein
| Name = 色氨酸羟化酶1（色氨酸5-单加氧酶）
| caption = 
| image = 
| width = 
| HGNCid = 12008
| Symbol = [[TPH1]]
| AltSymbols = TPRH, TPH
| EntrezGene = 7166
| OMIM = 191060
| RefSeq = NM_004179
| UniProt = P17752
| PDB = 1MLW
| ECnumber = 1.14.16.4
| Chromosome = 11
| Arm = p
| Band = 15.3
| LocusSupplementaryData = -p14
}}
{{protein
| Name = 色氨酸羟化酶2
| caption = 
| image = 
| width = 
| HGNCid = 20692
| Symbol = [[TPH2]]
| AltSymbols = 
| EntrezGene = 121278
| OMIM = 607478
| RefSeq = NM_173353
| UniProt = Q8IWU9
| PDB = 
| ECnumber = 
| Chromosome = 12
| Arm = q
| Band = 15
| LocusSupplementaryData = 
}}

'''色氨酸羟化酶'''（{{lang-en|Tryptophan hydroxylase}}，[[EC编号|EC]] [http://enzyme.expasy.org/EC/1.14.16.4 1.14.16.4] {{Wayback|url=http://enzyme.expasy.org/EC/1.14.16.4 |date=20201127150939 }}）也称为'''色氨酸5-单加氧酶'''，简称'''TPH'''，是合成[[神经递质]][[5-羟色胺]]的过程中重要的[[酶]]。色氨酸羟化酶可催化如下[[酶促反应]]：

: L-[[色氨酸]] + [[四氢生物蝶呤]] + O<sub>2</sub> <math>\rightleftharpoons</math> [[5-羟色氨酸]] + [[二氢生物蝶呤]] + H<sub>2</sub>O

以上反应还需要[[亚铁离子]]作为[[辅酶]]。

== 功能 ==
{{stack|
{{Enzymatic Reaction
|foward_enzyme=色氨酸羟化酶
|reverse_enzyme=
|substrate=[[色氨酸]]
|product=[[5-羟色氨酸]]
|reaction_direction_(forward/reversible/reverse)=forward
|minor_foward_substrate(s)=O<sub>2</sub><br />[[四氢生物蝶呤|BH<sub>4</sub>]]
|minor_foward_product(s)=H<sub>2</sub>O<br />BH<sub>2</sub>
|minor_reverse_substrate(s)=
|minor_reverse_product(s)=
|substrate_image=Tryptophan_simple.png
|substrate_image_size=120px
|product_image=5-hydroxytryptophan.png
|product_image_size=120px
}}
}}
色氨酸羟化酶可以使[[色氨酸]]的C<sub>5</sub>[[羟基化]]，使色氨酸转化为5-羟色氨酸（5-HTP）。这一催化氧化反应是神经递质5-羟色胺[[生物合成]]过程中的启示步及[[限速步]]。色氨酸羟化酶也是[[褪黑素]]生物合成过程中需要用到的第一种酶。 

色氨酸羟化酶（TPH）与[[酪氨酸羟化酶]]（TH）、[[苯丙氨酸羟化酶]]（PAH）等皆为[[芳香族氨基酸羟化酶]][[超家族]]（superfamily）的成员，负责催化重要[[代谢途径]]中的关键步骤。<ref name="pmid11747434">{{cite journal | author = McKinney J, Teigen K, Frøystein NA, Salaün C, Knappskog PM, Haavik J, Martínez A | title = Conformation of the substrate and pterin cofactor bound to human tryptophan hydroxylase. Important role of Phe313 in substrate specificity | journal = Biochemistry | volume = 40 | issue = 51 | pages = 15591–601 | pmid = 11747434 | doi = 10.1021/bi015722x | url = http://www.bh4.org/pdf/mckinney.pdf | date = December 2001 | deadurl = yes | archiveurl = https://web.archive.org/web/20081217045622/http://www.bh4.org/pdf/mckinney.pdf | archivedate = 2008-12-17 }}</ref>与酪氨酸羟化酶、苯丙氨酸羟化酶类似，色氨酸羟化酶也以(6''R'')-<small>L</small>-赤型-5,6,7,8-[[四氢生物蝶呤]]（BH<sub>4</sub>）及[[双氧]]（O<sub>2</sub>）作为氧化还原的底物。<ref name="urlBH4 Databases">{{cite web| url =http://www.bh4.org/BH4_Deficiency_Biochemistry.asp| title =tetrahydrobiopterin| author =| authorlink =| coauthors =| year =2005| format =| work =BH4 Databases| publisher =BH4.org| pages =| language =| archiveurl =https://web.archive.org/web/20061206195735/http://bh4.org/BH4_Deficiency_Biochemistry.asp| archivedate =2006-12-06| quote =| accessdate =| deadurl =yes}}</ref>

[[人类]]的色氨酸羟化酶若受到某些物质（如[[对氯苯丙氨酸]]）的抑制，可能会引发[[抑郁症]]。<ref name="pmid12379098">{{cite journal | author = Wang L, Erlandsen H, Haavik J, Knappskog PM, Stevens RC | title = Three-dimensional structure of human tryptophan hydroxylase and its implications for the biosynthesis of the neurotransmitters serotonin and melatonin | journal = Biochemistry | volume = 41 | issue = 42 | pages = 12569–74 | pmid = 12379098 | doi = 10.1021/bi026561f | url =  |date=October 2002}}</ref>

色氨酸羟化酶的[[酶活性]]（即色氨酸羟化酶将<small>L</small>-色氨酸转化为5-羟色胺[[前体]]<small>L</small>-5-羟色氨酸的[[反应速率]]）可以在被[[蛋白激酶A]]等[[激酶]]催化[[磷酸化]]后增加。

== 异构体 ==
[[哺乳动物]]都拥有两种不同的TPH[[基因]]。人类的两个TPH基因分别位于[[11号染色体 (人类)|11号染色体]]和[[12号染色体 (人类)|12号染色体]]上，它们编码着不同却同源的酶——[[TPH1]]及[[TPH2]]，这两种基因的序列一致性达71%。<ref name="pmid14563478">{{cite journal | author = Walther DJ, Bader M | title = A unique central tryptophan hydroxylase isoform | journal = Biochem. Pharmacol. | volume = 66 | issue = 9 | pages = 1673–80 | pmid = 14563478 | doi = 10.1016/S0006-2952(03)00556-2| url =  |date=November 2003}}</ref>

*TPH1主要[[基因表达|表达]]在分泌5-羟色胺的[[组织 (生物学)|组织]]中，如[[皮肤]]、[[肠 (解剖学)|肠道]]、[[松果体]]以及[[中枢神经系统]]中。
*TPH2则仅在[[神经细胞]]中表达，且其于中枢神经系统中的表达量较TPH1大。

== 参考文献 ==
<references/>

== 扩展阅读 ==
{{refbegin | 2}}
* {{cite journal | author = Friedman PA, Kappelman AH, Kaufman S | year = 1972 | title = Partial purification and characterization of tryptophan hydroxylase from rabbit hindbrain | journal = J. Biol. Chem.  | volume = 247 | pages = 4165–73  | pmid = 4402511 | issue = 13 }}
* {{cite journal | author = Hamon M, Bourgoin S, Artaud F, Glowinski J | year = 1979 | title = The role of intraneuronal 5-HT and of tryptophan hydroxylase activation in the control of 5-HT synthesis in rat brain slices incubated in K+-enriched medium | journal = J. Neurochem.  | volume = 33 | pages = 1031–42  | pmid = 315449 | doi = 10.1111/j.1471-4159.1979.tb05239.x | issue = 5 }}
* {{cite journal | author = Ichiyama A, Nakamura S, Nishizuka Y, Hayaishi O | year = 1970 | title = Enzymic studies on the biosynthesis of serotonin in mammalian brain | journal = J. Biol. Chem.  | volume = 245 | pages = 1699–709  | pmid = 5309585 | issue = 7 }}
* {{cite journal | author = Jequier E, Robinson DS, Lovenberg W, Sjoerdsma A | year = 1969 | title = Further studies on tryptophan hydroxylase in rat brainstem and beef pineal | journal = Biochem. Pharmacol.  | volume = 18 | pages = 1071–81  | pmid = 5789774 | doi = 10.1016/0006-2952(69)90111-7 | issue = 5 }}
* {{cite journal | author = Wang L, Erlandsen H, Haavik J, Knappskog PM, Stevens RC | year = 2002 | title = Three-dimensional structure of human tryptophan hydroxylase and its implications for the biosynthesis of the neurotransmitters serotonin and melatonin | journal = Biochemistry.  | volume = 41 | pages = 12569–74  | pmid = 12379098 | doi = 10.1021/bi026561f | issue = 42 }}
* {{cite journal | author = Windahl MS, Petersen CR, Christensen, HEM, Harris P | year = 2008 | title = Crystal Structure of Tryptophan Hydroxylase with Bound Amino Acid Substrate | journal = Biochemistry.  | volume = 47 | pages = 12087–94  | pmid = 18937498 | doi = 10.1021/bi8015263 | issue = 46}}
{{refend}}


{{双加氧酶}}
{{神经递质代谢酶类}}

[[Category:酶]]
[[Category:EC 1.14.16]]