2ZPP

Neutron crystal structure of cubic insulin at pD9

Summary for 2ZPP

• Entry DOI: 10.2210/pdb2zpp/pdb
• Related: 2EFA
• Descriptor: Insulin A chain, Insulin B chain (3 entities in total)
• Functional Keywords: hormone, cubic, porcine insulin, carbohydrate metabolism, cleavage on pair of basic residues, glucose metabolism, secreted
• Biological source: Sus scrofa (Pig); More
• Cellular location: Secreted: P01315 P01315
• Total number of polymer chains: 2
• Total formula weight: 5787.63

Authors

Ishikawa, T.,Tanaka, I.,Niimura, N. (deposition date: 2008-07-26, release date: 2008-10-28, Last modification date: 2024-10-23)

Primary citation

Ishikawa, T.,Chatake, T.,Morimoto, Y.,Maeda, M.,Kurihara, K.,Tanaka, I.,Niimura, N.
An abnormal pK(a) value of internal histidine of the insulin molecule revealed by neutron crystallographic analysis
Biochem.Biophys.Res.Commun., 376:32-35, 2008

PubMed Abstract: Insulin is stored in pancreatic beta-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 pK(a) 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.

PubMed: 18725203
DOI: 10.1016/j.bbrc.2008.08.071

Experimental method

NEUTRON DIFFRACTION (2.5 Å)