• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to project page

1989 Fiscal Year Final Research Report Summary

Insulin-modulating peptide from soybean protein: Identification of the component and the mechanism on biological activity

Research Project

Project/Area Number 63480055
Research Category

Grant-in-Aid for General Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field 応用生物化学・栄養化学
Research InstitutionNagoya University

Principal Investigator

MAKINO Shio  Nagoya Univ., Fac. of Agric., Professor, 農学部, 教授 (80000842)

Co-Investigator(Kenkyū-buntansha) MORIYAMA Ryuichi  Nagoya Univ., Fac. of Agric., Associate, 農学部, 助手 (60191061)
Project Period (FY) 1988 – 1989
KeywordsGlycinin acidic subunit / Bile acid-binding protein / Insulin-stimulating peptide / Stimulation of fat decomposition / Inhibition of insulin degradation
Research Abstract

Several lines of evidence had indicated that some component(s) of soybean protein participates in the modulation of lipid metabolism and that one of the hormones involved in the metabolism is insulin. We looked for soybean protein component(s) which is capable of affecting the insulin action. By sequencing of purified peptides and examination of their effects on fat decomposition in isolated rat adipocytes, it was confirmed that A_<1a> and A_2 acidic subunits of glycinin potentiate the action of insulin in vitro. In addition, the proteins showed an ability to bind bile acids. Thus, these proteins are probable candidates which exert the hypocholesterolemic effect, a well-known physiological function of soybean protein, by interfering with steroid adsorption. However, the bile acidbinding ability was not related to the insulin-stimulating activity. Both properties were noted in acidic subunits of legumin from pea seed, indicating that these characteristics may be common to legume proteins.
Trypsinized products of A_<1a> subunit (A_<1a>/TR) also exhibited the insulin-stimulating activity and the molecular mechanism was examined by using rat adipocytes. A_<1a>/TR did not affect the glucose transport, which is the primary process of insulin action on the cells.
However, A_<1a>/TR enhanced a reactivity and a sensitivity of fat decomposition to insulin.
Affinity of insulin to its receptor on the cell surface was not affected by A_<1a>/TR. A_<1a>/TR protected insulin from degradation, resulted in an increase of insulin concentration in the cells. The insulin-stimulating activities were not observed at 15゚C, indicating that the internarization of insulin is requisite for an appearance of the protein effect, and the inhibition of insulin degradation alone cannot account for the enhancing effect observed in the maximal responses to the hormone.

  • Research Products

    (6 results)

All Other

All Publications (6 results)

  • [Publications] Makino,Shio: "Acidic polypeptides of glycinin:Bile acid-binding properties and Insulin-stimulating activity" Proceedings of ISF-JOCS World Congress 1988. 2. 1158-1163 (1989)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Minami,Kohtaro: "Identification of soybean protein components that modulate the action of insulin in vitro" Agric.Biol.Chem.54. 511-517 (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Minami,Kohtaro: "Mechanism on the insulin stimulating action of soybean glycinin subunit in adipose cells" Biochim.Biophys.Res.Commun.(発表予定). (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Makino, Shio: "Acidic polypeptides of glycini: Bile acid-binding properties and insulin-stimulating activity." Proceedings of ISF-JOCS World Congress 1988, 2, 1158-1163 (1989).

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Minami, Kohtaro: "Identification of soybean protein components that modulate the action of insulin in vitro." Agric. Biol. Chem., 54, 511-517 (1990).

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Minami, Kohtaro: "Mechanism on the insulin stimulating action of soybean blycinin subunit in adipose cells." Biochim. Biopys. Res. Commun.

    • Description
      「研究成果報告書概要(欧文)」より

URL: 

Published: 1993-03-26  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi