| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1934288 | Biochemical and Biophysical Research Communications | 2008 | 4 Pages |
Abstract
Insulin is stored in pancreatic β-cell as hexameric form with Zn2+ ions, while the hormonally active form is monomer. The hexamer requires the coordination of Zn2+ ions to the HisB10. In order to reveal the mechanism of the hexamerization of insulin, we investigated the Zn2+ free insulin at pD6.6 and pD9 by neutron crystallographic analyses. HisB10 is doubly protonated not only at pD6.6 but also at pD9, indicating an abnormal pKa of this histidine. It is suggested that HisB10 acts on a strong cation capture and contributes to the high stability of the hexameric form in pancreas.
Related Topics
Life Sciences
Biochemistry, Genetics and Molecular Biology
Biochemistry
Authors
Takuya Ishikawa, Toshiyuki Chatake, Yukio Morimoto, Mitsuru Maeda, Kazuo Kurihara, Ichiro Tanaka, Nobuo Niimura,