著者

Ayako Hoshiyama Kazumi Fujimoto Ryo Konno Sayaka Sasaki Akari Momozono Yoshio Kodera Masayoshi Shichiri

出版者

The Japan Endocrine Society

雑誌

Endocrine Journal (ISSN:09188959)

巻号頁・発行日

pp.EJ18-0472, (Released:2019-04-26)

被引用文献数

3

---

Glucose-dependent insulinotropic polypeptide (GIP), secreted from enteroendocrine K cells, has potent insulin-releasing and extrapancreatic glucoregulatory activities. However, exogenous GIP has less potent biological effects compared with another incretin hormone, GLP-1, which limits its use for the treatment of type 2 diabetes. The fate and secretion of administered native GIP remain unclear. The aim of this study was to identify plasma binding proteins for human GIP. Fluorescent-labelled GIP was added to fresh human plasma and subjected to clear native polyacrylamide gel electrophoresis (CN-PAGE). Then fluorescent protein bands were in-gel trypsin-digested and subjected to liquid chromatography tandem-mass spectrometry (LC-MS/MS) analysis, revealing the presence of albumin, immunoglobulin G (IgG) and transferrin. In contrast to GIP, the binding of fluorescent GLP-1 and glucagon to plasma protein fractions were minimal. CN-PAGE analysis of synthetic GIP incubated with human serum albumin, purified IgG or transferrin, and subsequent western blot analysis revealed that GIP binds to each of these proteins. Taken together, these results indicate that GIP readily binds to albumin, IgG and transferrin, three plasma proteins highly abundant in the human peripheral circulation. Separation of protein complexes using CN-PAGE and the identification of in-gel digested proteins by LC-MS/MS analysis provide a promising strategy to identify plasma binding proteins for bioactive peptides.

著者

KAZUYUKI SOGAWA MIKA KOBAYASHI JUN SUZUKI AKIHIRO SANDA YOSHIO KODERA MASAFUMI FUKUYAMA

出版者

The Society for Antibacterial and Antifungal Agents, Japan

雑誌

Biocontrol Science (ISSN:13424815)

巻号頁・発行日

vol.23, no.2, pp.77-80, 2018 (Released:2018-06-16)

参考文献数

19

被引用文献数

2 4

---

Group A streptococcus is a bacterium that resides in the throat and skin and causes respiratory infection and occasionally glomerulonephritis and rheumatic fever. Streptolysin O (SLO) produced by Streptococcus pyogenes (S. pyogenes) binds to the cell membrane, particularly to that of white and red blood cells, and is toxic to the cells and tissue. In this study, we evaluated the inhibitory activity of water-soluble polyphenols in olives (Olea europaea) against SLO-induced hemolysis. Hydroxytyrosol inhibited SLO-induced hemolytic activity, and the amount required for 50% inhibition of hemolysis was 1.30 µg. These findings suggest that the water-soluble polyphenols contained in olives have inhibitory activity against SLO-induced hemolysis.