{"created":"2023-06-19T09:48:56.463910+00:00","id":5329,"links":{},"metadata":{"_buckets":{"deposit":"4be2c165-3ad8-4cdb-9010-c216f5113e41"},"_deposit":{"created_by":3,"id":"5329","owners":[3],"pid":{"revision_id":0,"type":"depid","value":"5329"},"status":"published"},"_oai":{"id":"oai:fukuyama-u.repo.nii.ac.jp:00005329","sets":["502:506:514:517"]},"author_link":["26273","26275","26274"],"item_1_biblio_info_14":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2000-12","bibliographicIssueDateType":"Issued"},"bibliographicPageEnd":"57","bibliographicPageStart":"1","bibliographicVolumeNumber":"11","bibliographic_titles":[{"bibliographic_title":"福山大学内海生物資源研究所報告"}]}]},"item_1_creator_6":{"attribute_name":"著者名(日)","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"北口, 博隆"}],"nameIdentifiers":[{"nameIdentifier":"26273","nameIdentifierScheme":"WEKO"}]}]},"item_1_description_1":{"attribute_name":"ページ属性","attribute_value_mlt":[{"subitem_description":"P(論文)","subitem_description_type":"Other"}]},"item_1_description_11":{"attribute_name":"抄録(日)","attribute_value_mlt":[{"subitem_description":"DMSPの生理機能の一つは浸透圧調節であると考えられている。渦鞭毛藻C. cohniiを用いて,浸透圧変化の要因として塩濃度の変動にともなう細胞内DMSP量の変動,またC. cohniiのDMSP生合成経路の鍵酵素と考えられるメチオニン脱炭酸酵素の比活性の変動について検討した。C. cohniiは,1.5%NaClから3.5%NaClの範囲で,塩濃度が低いほど良い増殖を示した。これはC. cohniiが汽水域の貯木場などに生息する種であることを反映していると考えられた。また,塩濃度が高いほど細胞内DMSP量,メチオニン脱炭酸酵素の比活性は高いという傾向がみられ,高浸透圧条件ではDMSP量を能動的に高く維持して適応する機構が存在することが示唆された。培地の塩濃度の変化にともなうCeoo加ガ細胞内DMSP量,メチオニン脱炭酸酵素の比活性,および細胞外DMS量の変化を検討したところ,低塩濃度から高塩濃度の培地に移して6時間後には細胞内DMSP量,メチオニン脱炭酸酵素の比活性は2倍程度上昇した。高塩濃度から低塩濃度の培地に移して6時間後には細胞内DMSP量,メチオニン脱炭酸酵素活性は約半分に減少し,そのとき細胞外DMS濃度は3倍以上上昇した。これらの結果から,C. cohniiは,細胞外の浸透圧が上昇するとDMSP合成系の活性化によって細胞内DMSP量を増加させて細胞内の浸透圧を高め,逆に細胞外の浸透圧が下がるとDMSP合成系の抑制,分解系の活性化により細胞内DMSP量を減少させて細胞内の浸透圧を下げて新たな浸透圧条件に適応するのではないかと考えられた。また,C. cohniiは浸透圧変化によって6時間以内にDMSP量を変動させることから,C. cohniiにおいてDMSPは,緑藻E. intestinalisにおけるsteady stateでの浸透圧調節機構iとは異なる機構に関与していることが示唆された。","subitem_description_type":"Other"}]},"item_1_description_12":{"attribute_name":"抄録(英)","attribute_value_mlt":[{"subitem_description":"Dimethylsulfide (DMS) is the major sulfur compound released from ocean to the atmosphere. As 80 % of biogenic sulfur emitted from ocean is DMS, it has significance for the global sulfur cycle. However, the conversion of sulfate to DMS was the missing link in the global sulfur cycle. Emitted DMS is oxidized to sulfate which plays an important role in cloud formation, thereby it may commit to the acid precipitation and the climate regulation. It is generally thought that the precursor of DMS is dimethylsulfoniopropionate (DMSP), which is cleaved enzymatically or in alkaline condition to produce DMS and acrylate. DMSP is a growth promotive compound for fish, and acts as an anti ulcer agent in rat. The primary DMSP producers are marine macro- and microalgae, and the possible biological function of DMSP in algae is osmolyte. But the mechanism controlling DMSP pool is still unknown. Investigation of the DMSP biosynthesis has significance in understanding the missing link in global sulfur cycle and the osmoregulation mechanism, however the biosynthetic pathway of DMSP has been little known. Recently, two pathways were reported. One of them was found in a flowering plant Wollastonia biflora which produce DMSP from S-methylmethionine (SMM) and the other was found in a green alga Enteromorpha intestinalis which produce DMSP via 4-methylthio-2-oxobutylate (MTOB). These results suggest that the several pathways exist in DMSP biosynthesis. In this study, the dinoflagellate Crypthecodinium cohnii, the producer of a large amount of DMSP, was used for investigating the biosynthesis of DMSP. The results obtained in this study are described below: (1) The incorporation of L -methionine into DMSP was examined by the in vivo radiotracer experiments. In two hour incubation, the methyl, C3, and C4 carbons, and the sulfur atom of L -methionine were effectively incorporated into DMSP. But the C1 carbon of L -methionine was not incorporated into DMSP. These results suggest that L- methionine is the close precursor of DMSP and the synthetic pathway is consistent of decarboxylation, deamination followed by oxidation, and methylation. (2) The dilution effects of SMM, MTOB, and 3-methilthiopropionate (MTP) to the incorporation of L-methionine into DMSP was examined. SMM and MTOB did not affect the incorporation of L-methionine into DMSP. But MTP strongly inhibited the incorporation of L-methionine into DMSP. These results suggest that the pathway is the conversion of L-methionine into DMSP by decarboxylation (the putative product is 3-methylthiopropanamine (MTPA)), deamination followed by oxidation (the putative product is MTP), and methylation (the putative product is DMSP) in this order. (3) The enzymatic activities of decarboxylation of L-methionine, deamination followed by oxidation of MTPA, and methylation of MTP were detected in the crude extract of C. cohnii. These results confirm the evidence of this pathway in C. cohnii. (4) L-Methionine decarboxylase [EC 4.1.1.57], which should be the key enzyme in DMSP biosynthesis from L -methionine, was purified from C. cohnii. After four purification steps including anion exchange chromatography and size-exclusion chromatography, the enzyme was purified 215-fold and the yield was 0.1%. The purified enzyme showed a single protein band on polyacrylamide gel electrophoresis (PAGE). The molecular weight of the enzyme estimated by gel filtration was 204,000 and that estimated by SDS-PAGE was 100,000. The optimum pH of the enzyme was pH7.3. The optimum temperature of the enzyme was 30℃. The enzyme was pyridoxal 5'-phosphate dependent decarboxylase. The N-terminal amino acid sequence of the enzyme was Ala-Leu- Cys- Trp- Ser- Asp- Ile- Ser- Pro. The decarboxylated product of L-methionine by the enzyme was MTPA (5) To investigate the physiological role of DMSP in C. cohnii, the effects of salinity changes on intracellular DMSP content and L -methionine decarboxylase activity were determined. The salinity upshift resulted the accumulation of DMSP in cells. The methionine decarboxylase activity was also stimulated by the salinity upshift. These results suggest that the high osmolarity stimulates the production of DMSP and DMSP acts as the osmoprotectant in C cohnii. But the evidence that the accumulation of DMSP occurred rapidly in high salinity than in E intestinalis suggests the regulation mechanisms of these organisms are different. It may be due to the difference of DMSP biosynthetic pathway.","subitem_description_type":"Other"}]},"item_1_full_name_7":{"attribute_name":"著者名よみ","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"26274","nameIdentifierScheme":"WEKO"}],"names":[{"name":"キタグチ, ヒロタカ"}]}]},"item_1_full_name_8":{"attribute_name":"著者名(英)","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"26275","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Kitaguchi, Hirotaka","nameLang":"en"}]}]},"item_1_source_id_13":{"attribute_name":"雑誌書誌ID","attribute_value_mlt":[{"subitem_source_identifier":"AA1157543X","subitem_source_identifier_type":"NCID"}]},"item_1_text_10":{"attribute_name":"著者所属(英)","attribute_value_mlt":[{"subitem_text_language":"en","subitem_text_value":"Department of Marine Biotechnology, Fukuyama University"}]},"item_1_text_2":{"attribute_name":"記事種別(日)","attribute_value_mlt":[{"subitem_text_value":"原著論文"}]},"item_1_text_3":{"attribute_name":"記事種別(英)","attribute_value_mlt":[{"subitem_text_language":"en","subitem_text_value":"Original"}]},"item_1_text_9":{"attribute_name":"著者所属(日)","attribute_value_mlt":[{"subitem_text_value":"福山大学海洋生物工学科"}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2000-12-01"}],"displaytype":"detail","filename":"KJ00005780250.pdf","filesize":[{"value":"3.6 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"url":"https://fukuyama-u.repo.nii.ac.jp/record/5329/files/KJ00005780250.pdf"},"version_id":"f09ee681-dc08-4707-b243-da7caac5083d"}]},"item_keyword":{"attribute_name":"キーワード","attribute_value_mlt":[{"subitem_subject":"生合成","subitem_subject_scheme":"Other"},{"subitem_subject":"二面性溶質","subitem_subject_scheme":"Other"},{"subitem_subject":"脱炭酸酵素","subitem_subject_scheme":"Other"},{"subitem_subject":"硫化ジメチル","subitem_subject_scheme":"Other"},{"subitem_subject":"ジメチルスルフォニオプロピオン酸","subitem_subject_scheme":"Other"},{"subitem_subject":"渦鞭毛藻","subitem_subject_scheme":"Other"},{"subitem_subject":"メチオニン","subitem_subject_scheme":"Other"},{"subitem_subject":"浸透圧調節","subitem_subject_scheme":"Other"},{"subitem_subject":"biosynthesis","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"compatible solute","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"Cryptheeodinium cohnii","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"decarboxylase","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"dimethyl sulfide","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"dimethylsulfbniopropionate","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"dinoflagellate","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"L-methionine","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"osmoprotectant","subitem_subject_language":"en","subitem_subject_scheme":"Other"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"departmental bulletin paper","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"海産渦鞭毛藻Crypthecodinium cohniiにおけるジメチルスルフォニオプロピオン酸の生合成に関する研究","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"海産渦鞭毛藻Crypthecodinium cohniiにおけるジメチルスルフォニオプロピオン酸の生合成に関する研究"},{"subitem_title":"Studies on the Biosynthesis of Dimethylsulfoniopropionate in the Dinoflagellate Crypthecodinium cohnii","subitem_title_language":"en"}]},"item_type_id":"1","owner":"3","path":["517"],"pubdate":{"attribute_name":"公開日","attribute_value":"2000-12-01"},"publish_date":"2000-12-01","publish_status":"0","recid":"5329","relation_version_is_last":true,"title":["海産渦鞭毛藻Crypthecodinium cohniiにおけるジメチルスルフォニオプロピオン酸の生合成に関する研究"],"weko_creator_id":"3","weko_shared_id":-1},"updated":"2023-06-19T11:26:07.637156+00:00"}