Scholarlink

<p>Red algae are photosynthetic eukaryotes whose light-harvesting complexes (LHCs) associate with photosystem I (PSI). In this study, we examined characteristics of PSI-LHCI, PSI, and LHCI isolated from the red alga <i>Galdieria sulphuraria</i> NIES-3638. The PSI-LHCI supercomplexes were purified using anion-exchange chromatography followed by hydrophobic-interaction chromatography, and finally by trehalose density gradient centrifugation. PSI and LHCI were similarly prepared following the dissociation of PSI-LHCI with Anzergent 3–16. Polypeptide analysis of PSI-LHCI revealed the presence of PSI and LHC proteins, along with red-lineage chlorophyll <i>a</i>/<i>b</i>-binding-like protein (RedCAP), which is distinct from LHC proteins within the LHC protein superfamily. RedCAP, rather than LHC proteins, exhibited tight binding to PSI. Carotenoid analysis of LHCI identified zeaxanthin, <i>β</i>-cryptoxanthin, and <i>β</i>-carotene, with zeaxanthin particularly enriched, which is consistent with other red algal LHCIs. A Qy peak of chlorophyll <i>a</i> in the LHCI absorption spectrum was blue-shifted compared with those of PSI-LHCI and PSI, and a fluorescence emission peak was similarly shifted to shorter wavelengths. Based on these results, we discuss the diversity of LHC proteins and RedCAP in red algal PSI-LHCI supercomplexes.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Biochemical evidence for the diversity of LHCI proteins in PSI-LHCI from the red alga Galdieria sulphuraria NIES-3638

  • 期刊论文

  • 发表日期：

    2025年1月27日

查看全文
  • Ryo Nagao,
  • Haruya Ogawa,
  • Takehiro Suzuki,
  • Naoshi Dohmae,
  • Koji Kato,
  • Yoshiki Nakajima,
  • Jian-Ren Shen

摘要

Red algae are photosynthetic eukaryotes whose light-harvesting complexes (LHCs) associate with photosystem I (PSI). In this study, we examined characteristics of PSI-LHCI, PSI, and LHCI isolated from the red alga Galdieria sulphuraria NIES-3638. The PSI-LHCI supercomplexes were purified using anion-exchange chromatography followed by hydrophobic-interaction chromatography, and finally by trehalose density gradient centrifugation. PSI and LHCI were similarly prepared following the dissociation of PSI-LHCI with Anzergent 3–16. Polypeptide analysis of PSI-LHCI revealed the presence of PSI and LHC proteins, along with red-lineage chlorophyll a/b-binding-like protein (RedCAP), which is distinct from LHC proteins within the LHC protein superfamily. RedCAP, rather than LHC proteins, exhibited tight binding to PSI. Carotenoid analysis of LHCI identified zeaxanthin, β-cryptoxanthin, and β-carotene, with zeaxanthin particularly enriched, which is consistent with other red algal LHCIs. A Qy peak of chlorophyll a in the LHCI absorption spectrum was blue-shifted compared with those of PSI-LHCI and PSI, and a fluorescence emission peak was similarly shifted to shorter wavelengths. Based on these results, we discuss the diversity of LHC proteins and RedCAP in red algal PSI-LHCI supercomplexes.