[PMID]: | 28627163 |
[Au] Autor: | Mizoguchi T; Isaji M; Yamano N; Harada J; Fujii R; Tamiaki H |
[Ad] Endereço: | Graduate School of Life Sciences, Ritsumeikan University , Kusatsu, Shiga 525-8577, Japan. |
[Ti] Título: | Molecular Structures and Functions of Chlorophylls-a Esterified with Geranylgeranyl, Dihydrogeranylgeranyl, and Tetrahydrogeranylgeranyl Groups at the 17-Propionate Residue in a Diatom, Chaetoceros calcitrans. |
[So] Source: | Biochemistry;56(28):3682-3688, 2017 Jul 18. |
[Is] ISSN: | 1520-4995 |
[Cp] País de publicação: | United States |
[La] Idioma: | eng |
[Ab] Resumo: | The 17-propionate ester group of chlorophyll(Chl)-a in some oxygenic phototrophs was investigated using HPLC. Chls-a esterified with partially dehydrogenated forms of a phytyl group were found in fully grown cells of a diatom, Chaetoceros calcitrans: geranylgeranyl (GG), dihydrogeranylgeranyl (DHGG), and tetrahydrogeranylgeranyl (THGG). Chls-a bearing such esterifying groups were reported to be found only in greening processes of higher plants, and thus these Chls-a have been thought to be biosynthetic precursors for phytylated Chl-a. Their molecular structures were unambiguously determined using H and C NMR spectroscopy and mass spectrometry. In particular, the positions of Câ•C double bonds in DHGG were identified at C2â•C3, C6â•C7, and C14â•C15, and those in THGG were determined to be at C2â•C3 and C14â•C15. Notably, the present DHGG was different from the previously determined DHGG of bacteriochlorophyll-a in purple bacteria (C2â•C3, C10â•C11, and C14â•C15). Moreover, thylakoid membranes as well as fucoxanthin-chlorophyll-a/c proteins called FCPs were isolated from the diatom, and their Chl-a compositions were analyzed. Chls-a esterified with GG, DHGG, and THGG were detected by HPLC, indicating that such Chls-a were not merely biosynthetic precursors, but photosynthetically active pigments. |
[Mh] Termos MeSH primário: |
Clorofila/química Diatomáceas/química Tilacoides/química
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[Mh] Termos MeSH secundário: |
Esterificação Hordeum/química Prenilação Propionatos/análise
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[Pt] Tipo de publicação: | JOURNAL ARTICLE |
[Nm] Nome de substância:
| 0 (Propionates); 1406-65-1 (Chlorophyll); YF5Q9EJC8Y (chlorophyll a) |
[Em] Mês de entrada: | 1708 |
[Cu] Atualização por classe: | 170804 |
[Lr] Data última revisão:
| 170804 |
[Sb] Subgrupo de revista: | IM |
[Da] Data de entrada para processamento: | 170620 |
[St] Status: | MEDLINE |
[do] DOI: | 10.1021/acs.biochem.7b00381 |
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