プロリンラセマーゼのソースを表示

{{enzyme
| Name = proline racemase
| EC_number = 5.1.1.4
| CAS_number = 9024-09-3
| IUBMB_EC_number = 5/1/1/4
| GO_code = 0018112
| image = 
| width = 
| caption = 
}}'''プロリンラセマーゼ''' (Proline racemase、{{EC number|5.1.1.4}}) は、以下の[[化学反応]]を[[触媒]]する[[酵素]]である。
:L-プロリン <math>\rightleftharpoons</math> D-プロリン

従って、基質はL-[[プロリン]]またはD-プロリン、生成物はD-プロリンまたはL-プロリンである。

系統名は'''プロリンラセマーゼ'''である。この酵素は、[[アルギニン]]及びプロリンの代謝に関与している。また、[[細菌]]においては、L-プロリンとD-プロリンの相互変換を触媒している<ref name="pmid3755058">{{cite journal | author = Fisher LM, Albery WJ, Knowles JR | title = Energetics of proline racemase: racemization of unlabeled proline in the unsaturated, saturated, and oversaturated regimes | journal = Biochemistry | volume = 25 | issue = 9 | pages = 2529-37 | year = 1986 | month = May | pmid = 3755058 | doi = 10.1021/bi00357a037 }}</ref>。

==種の分布==
最初に同定された[[真核生物]]のプロリンラセマーゼは、[[クルーズトリパノソーマ]](''Trypanosoma cruzi'')のものであり、Q9NCP4として登録された。この[[寄生虫]]の酵素''Tc''PRACは、[[補因子]]を必要としないプロリンラセマーゼで、''T. cruzi''が感染してこの酵素が放出されると、[[B細胞]]を[[細胞分裂]]させ、寄生虫が逃げるのを助けた<ref name="pmid10932226">{{cite journal | author = Reina-San-Martin B, Degrave W, Rougeot C, Cosson A, Chamond N, Cordeiro-Da-Silva A, Arala-Chaves M, Coutinho A, Minoprio P | title = A B-cell mitogen from a pathogenic trypanosome is a eukaryotic proline racemase | journal = Nat. Med. | volume = 6 | issue = 8 | pages = 890-7 | year = 2000 | month = August | pmid = 10932226 | doi = 10.1038/78651 }}</ref><ref name="pmid16164548">{{cite journal | author = Chamond N, Goytia M, Coatnoan N, Barale JC, Cosson A, Degrave WM, Minoprio P | title = Trypanosoma cruzi proline racemases are involved in parasite differentiation and infectivity | journal = Mol. Microbiol. | volume = 58 | issue = 1 | pages = 46-60 | year = 2005 | month = October | pmid = 16164548 | doi = 10.1111/j.1365-2958.2005.04808.x }}</ref>。

医学上及び獣医学上で重要なプロリンラセマーゼには、''Clostridium difficile''のQ17ZY4<ref name="pmid17849014">{{cite journal | author = Goytia M, Chamond N, Cosson A, Coatnoan N, Hermant D, Berneman A, Minoprio P | title = Molecular and structural discrimination of proline racemase and hydroxyproline-2-epimerase from nosocomial and bacterial pathogens | journal = PLoS ONE | volume = 2 | issue = 9 | pages = e885 | year = 2007 | pmid = 17849014 | pmc = 1964878 | doi = 10.1371/journal.pone.0000885 }}</ref>や''Trypanosoma vivax''のB8LFE4がある<ref name="pmid19428664">{{cite journal | author = Chamond N, Cosson A, Coatnoan N, Minoprio P | title = Proline racemases are conserved mitogens: characterization of a Trypanosoma vivax proline racemase | journal = Mol. Biochem. Parasitol. | volume = 165 | issue = 2 | pages = 170-9 | year = 2009 | month = June | pmid = 19428664 | doi = 10.1016/j.molbiopara.2009.02.002 }}</ref>。

==構造==
プロリンラセマーゼの生化学機構は、1960年代にCardinaleとAbelesにより<ref name="pmid5722267">{{cite journal | author = Cardinale GJ, Abeles RH | title = Purification and mechanism of action of proline racemase | journal = Biochemistry | volume = 7 | issue = 11 | pages = 3970-8 | year = 1968 | month = November | pmid = 5722267 | doi = 10.1021/bi00851a026 }}</ref>、''Clostridium sticklandii''の''Cs''PRACを用いて研究が進められた。2006年には、''Tc''PRACを[[競合阻害剤]]として知られていた[[ピロールカルボン酸]]とともに共結晶化して構造を解いたBuschiazzo、Goytiaらにより修正された<ref name="pmid16446443">{{PDB|1W61}} and {{PDB|1W62}}; {{cite journal | author = Buschiazzo A, Goytia M, Schaeffer F, Degrave W, Shepard W, Gregoire C, Chamond N, Cosson A, Berneman A, Coatnoan N, Alzari PM, Minoprio P | title = Crystal structure, catalytic mechanism, and mitogenic properties of Trypanosoma cruzi proline racemase | journal = Proc. Natl. Acad. Sci. U.S.A. | volume = 103 | issue = 6 | pages = 1705-10 | year = 2006 | month = February | pmid = 16446443 | pmc = 1413642 | doi = 10.1073/pnas.0509010103 }}</ref>。これらの研究により、酵素は2つの触媒ポケットを持つことが示された。その後、[[等温滴定型熱量計]]により、溶液中でピロールカルボン酸2分子が''Tc''PRACと結合し、恐らくは負の協同性の機構のためこの結合が時間依存であることが示された。さらに生化学上の新しい知見も、単量体に[[活性部位]]が2つあることと合致し、それまでの単量体当たり1つの活性部位という見方に変更を迫った<ref name="pmid3718964">{{cite journal | author = Albery WJ, Knowled JR | title = Energetics and mechanism of proline racemase | journal = Biochemistry | volume = 25 | issue = 9 | pages = 2572-7 | year = 1986 | month = May | pmid = 3718964 | doi = 10.1021/bi00357a043}}</ref>。

==出典==
{{reflist}}

==関連文献==
{{refbegin}}
* {{cite journal | author = Stadtman TC and Elliott P | title = Studies on the enzymic reduction of amino acids. II. Purification and properties of D-proline reductase and a proline racemase from ''Clostridium sticklandii'' | journal = J. Biol. Chem. | volume = 228 | issue = 2 | pages = 983-97 | year = 1957 | month = October | pmid = 13475375 | doi =  }}
* {{cite journal | author = Stenta M, Calvaresi M, Altoe P, Spinelli D, Garavelli M, Bottoni A | title = The catalytic activity of proline racemase: a quantum mechanical/molecular mechanical study | journal = J Phys Chem B | volume = 112 | issue = 4 | pages = 1057-9 | year = 2008 | month = January | pmid = 18044876 | doi = 10.1021/jp7104105 }}
* {{cite journal | author = Chamond N, Goytia M, Coatnoan N, Barale JC, Cosson A, Degrave WM, Minoprio P | title = Trypanosoma cruzi proline racemases are involved in parasite differentiation and infectivity | journal = Mol. Microbiol. | volume = 58 | issue = 1 | pages = 46-60 | year = 2005 | month = October | pmid = 16164548 | doi = 10.1111/j.1365-2958.2005.04808.x }}
* {{cite journal | author = Chamond N, Cosson A, Blom-Potar MC, Jouvion G, D'Archivio S, Medina M, Droin-Bergere S, Huerre M, Goyard S, Minoprio P | title = Trypanosoma vivax infections: pushing ahead with mouse models for the study of Nagana. I. Parasitological, hematological and pathological parameters | journal = PLoS Negl Trop Dis | volume = 4 | issue = 8 | pages = e792 | year = 2010 | pmid = 20706595 | pmc = 2919405 | doi = 10.1371/journal.pntd.0000792 }}
* {{cite journal | author = Blom-Potar MC, Chamond N, Cosson A, Jouvion G, Droin-Bergere S, Huerre M, Minoprio P | title = Trypanosoma vivax infections: pushing ahead with mouse models for the study of Nagana. II. Immunobiological dysfunctions | journal = PLoS Negl Trop Dis | volume = 4 | issue = 8 | pages = | year = 2010 | pmid = 20711524 | pmc = 2919407 | doi = 10.1371/journal.pntd.0000793 }}
* {{cite journal | author = Conti P, Tamborini L, Pinto A, Blondel A, Minoprio P, Mozzarelli A, De Micheli C | title = Drug Discovery Targeting Amino Acid Racemases | journal = Chem Rev | volume = 111| issue = 11| pages = 6919-46| year = 2011 | month = September | pmid = 21913633 | doi = 10.1021/cr2000702 }}
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{{デフォルトソート:ふろりんらせませ}}
[[Category:EC 5.1.1]]