2B4N: Solution Structure of Glucose-Dependent Insulinotropic Polypeptide

Citation:
Abstract
Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone that stimulates the secretion of insulin after ingestion of food. GIP also promotes the synthesis of fatty acids in adipose tissue. Therefore, it is not surprising that numerous literature reports have shown that GIP is linked to diabetes and obesity-related diseases. In this study, we present the solution structure of GIP in water determined by NMR spectroscopy. The calculated structure is characterized by the presence of an alpha-helical motif between residues Ser(11) and Gln(29). The helical conformation of GIP is further supported by CD spectroscopic studies. Six GIP-(1-42)Ala(1-7) analogues were synthesized by replacing individual N-terminal residues with alanine. Alanine scan studies of these N-terminal residues showed that the GIP-(1-42)Ala(6) was the only analogue to show insulin-secreting activity similar to that of the native GIP. However, when compared with glucose, its insulinotropic ability was reduced. For the first time, these NMR and modeling results contribute to the understanding of the structural requirements for the biological activity of GIP.
PDB ID: 2B4NDownload
MMDB ID: 38568
PDB Deposition Date: 2005/9/26
Updated in MMDB: 2007/11
Experimental Method:
solution nmr
Source Organism:
Similar Structures:
Molecular Components in 2B4N
Label Count Molecule
Protein (1 molecule)
1
Gastric Inhibitory Polypeptide(Gene symbol: GIP)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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