title: Characterization of a cellular immunostimulating peptide from a soybean protein fraction digested with peptidase R.
abstract: An immunostimulating glutamine-rich peptide was purified from a soybean protein fraction digested with Peptidase R produced by Rhizopus oryzae (Ro-digest) by a combination of SP-Sepharose column chromatography and reversed-phase high-performance liquid chromatography. The purified peptide was supposed to be located at or near the glutamine-rich region 202 to 222 of the glycinin G4 subunit. The peptide significantly increased the number of CD8(+), CD11b(+), and CD49b(+) cells in C3H/HeN mouse spleen cell cultures, while 2 chemically synthesized glutamine-rich peptides corresponding to residues 202 to 213 (QQQQQQKSHGGR) and residues 214 to 225 (KQGQHQQEEEEE) of the glycinin G4 subunit increased the number of interleukin (IL)-12(+)CD11b(+) cells. The peptide 202-213 also significantly increased the number of CD49b(+), IL-2(+)CD4(+), and interferon-gamma(+)CD4(+) cells and stimulated the cytotoxic activity of spleen cells toward the human erythroleukemia cell line K562. These results indicate that the glutamine-rich region of the soybean glycinin G4 subunit stimulates the cellular immune system in mouse spleen cell cultures.
authors.affiliation: Interdisciplinary Graduate School of Science and Technology, Shinshu University, Nagano, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Egusa
authors.forename: Hajime
authors.initials: H
authors.lastname: Otani
mesh_terms: D000276:Adjuvants, Immunologic / Q000302:isolation & purification* / Q000627:therapeutic use; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D002845:Chromatography; D005973:Glutamine; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D018664:Interleukin-12 / Q000378:metabolism; D020014:K562 Cells; D007938:Leukemia / Q000188:drug therapy / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D010447:Peptide Hydrolases / Q000378:metabolism; D010455:Peptides / Q000276:immunology* / Q000302:isolation & purification / Q000627:therapeutic use; D021122:Protein Subunits; D012233:Rhizopus; D030262:Soybean Proteins / Q000737:chemistry* / Q000494:pharmacology; D013025:Glycine max / Q000737:chemistry*; D013154:Spleen / Q000166:cytology / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D015703:Antigens, CD; D010455:Peptides; D021122:Protein Subunits; D030262:Soybean Proteins; D005973:Glutamine; D018664:Interleukin-12; D007371:Interferon-gamma; D010447:Peptide Hydrolases