Identification of Rubisco anxiolytic-like peptides (rALPs) by comprehensive analysis of spinach green leaf protein digest

  • Biochem Biophys Res Commun. 2018 Nov 10;505(4):1050-1056. doi: 10.1016/j.bbrc.2018.09.195.
Saeko Kimura  1 ,  Tomoki Uchida  1 ,  Yuki Tokuyama  1 ,  Mayumi Hosokawa  1 ,  Junya Nakato  1 ,  Atsushi Kurabayashi  2 ,  Masaru Sato  2 ,  Hideyuki Suzuki  2 ,  Ryuhei Kanamoto  1 ,  Kousaku Ohinata  3
Affiliations
  • 1. Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Japan.
  • 2. Department of Research & Development, Kazusa DNA Research Institutes, Japan.
  • 3. Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Japan. Electronic address: [email protected].
PMID: 30314694 DOI: 10.1016/j.bbrc.2018.09.195
Abstract

Rubisco, an enzyme for photosynthetic carbon dioxide fixation, is a major green leaf protein and known as the most abundant protein on the Earth. We found that Rubisco digested mimicking gastrointestinal enzymatic conditions exhibited anxiolytic-like effects after oral administration in mice. Based on a comprehensive peptide analysis of the digest using nanoLC-Orbitrap-MS and the structure-activity relationship of known anxiolytic-like peptides, we identified SYLPPLTT, SYLPPLT and YHIEPV [termed Rubisco anxiolytic-like peptide (rALP)-1, rALP-1(1-7) and rALP-2, respectively], which exhibited potent anxiolytic-like effects after oral administration. The anxiolytic-like effects of rALP-1/rALP-1(1-7) were blocked by a serotonin 5-HT1A receptor antagonist, whereas rALP-2-induced effects were inhibited by a δ-opioid receptor antagonist. In conclusion, novel Rubisco-derived anxiolytic-like peptides, rALP-1/rALP-1(1-7) and rALP-2, act via independent neural pathways.

Keywords
Anxiolytic-like effect; Comprehensive analysis; Green leaf; Oral administration; Peptide; Rubisco.
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