title: Identification of the bioactive and consensus peptide motif from Momordica charantia insulin receptor-binding protein.
abstract: Many food bioactive peptides with diverse functions have been discovered by studying plant proteins. We have previously identified a 68-residue insulin receptor (IR)-binding protein (mcIRBP) from Momordica charantia that exhibits hypoglycemic effects in mice via interaction with IR. By in vitro digestion, we found that mcIRBP-19, spanning residues 50-68 of mcIRBP, enhanced the binding of insulin to IR, stimulated the phosphorylation of PDK1 and Akt, induced the expression of glucose transporter 4, and stimulated both the uptake of glucose in cells and the clearance of glucose in diabetic mice. Furthermore, mcIRBP-19 homologs were present in various plants and shared similar β-hairpin structures and IR kinase-activating abilities to mcIRBP-19. In conclusion, our findings suggested that mcIRBP-19 is a blood glucose-lowering bioactive peptide that exhibits IR-binding potentials. Moreover, we newly identified novel IR-binding bioactive peptides in various plants which belonged to different taxonomic families.
authors.affiliation: Graduate Institute of Chinese Medicine, China Medical University, Taichung 40402, Taiwan.
authors.forename: Hsin-Yi
authors.initials: HY
authors.lastname: Lo
authors.affiliation: Graduate Institute of Chinese Medicine, China Medical University, Taichung 40402, Taiwan.
authors.forename: Chia-Cheng
authors.initials: CC
authors.lastname: Li
authors.affiliation: Graduate Institute of Chinese Medicine, China Medical University, Taichung 40402, Taiwan; Department of Health and Nutrition Biotechnology, Asia University, Taichung 41354, Taiwan. Electronic address: tyh@mail.cmu.edu.tw.
authors.forename: Tin-Yun
authors.initials: TY
authors.lastname: Ho
authors.affiliation: Department of Microbiology, China Medical University, Taichung 40402, Taiwan. Electronic address: cyhsiang@mail.cmu.edu.tw.
authors.forename: Chien-Yun
authors.initials: CY
authors.lastname: Hsiang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002460:Cell Line; D017124:Conserved Sequence; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000737:chemistry* / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D029777:Momordica charantia / Q000737:chemistry*; D010766:Phosphorylation; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D011972:Receptor, Insulin / Q000737:chemistry / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D010940:Plant Proteins; D011972:Receptor, Insulin
keywords: Bioactive peptide motif; Hypoglycemic; Insulin receptor-binding protein; β hairpin