User:SaraKathryn Kalkhoff/Sandbox 1

Introduction

The Gastric Inhibitory Polypeptide is a ligand that can be bound to its receptor (GIP-R) to help facilitate the breakdown of glucose. This is the basis of what makes up one of the key ways that glucose is bound and broken down into different parts, including insulin, to be able to maintain blood glucose levels within the body.

Figure 1: Main Structure of the Gastric Inhibitory Polypeptide Receptor (GIP-R).

Function

The GIP receptor helps facilitate movement of glucose within a cell. ^[1].

Tirzepatide

Tirzepatide has been used as a treatment for Type 2 diabetes. It is used to help treat Type 2 Diabetes, as an agonist to allow insulin to be broken down.

Disease

Diabetes is very bad for you^[2].

Relevance

Structural highlights

Active Site

Main binding domains between tirzepatide and the GIP receptor would contain an arginine 190 and glutamine 220 residues to facilitate binding of the ligand. One key difference found was a point mutation at position 7 between an Isoleucine and Threonine ^[1], which would result in a higher affinity for the tirzepatide molecule binding onto the receptor than the ligand.

Figure 2: Key difference between GIP ligand and Tirzepatide at position 7. Ile7 is in pink (ligand), and Thr7 is in green (tirzepatide).

References

1. ↑ ^{1.0 1.1} Sun B, Willard FS, Feng D, Alsina-Fernandez J, Chen Q, Vieth M, Ho JD, Showalter AD, Stutsman C, Ding L, Suter TM, Dunbar JD, Carpenter JW, Mohammed FA, Aihara E, Brown RA, Bueno AB, Emmerson PJ, Moyers JS, Kobilka TS, Coghlan MP, Kobilka BK, Sloop KW. Structural determinants of dual incretin receptor agonism by tirzepatide. Proc Natl Acad Sci U S A. 2022 Mar 29;119(13):e2116506119. PMID:35333651 doi:10.1073/pnas.2116506119
2. ↑ Ransey E, Paredes E, Dey SK, Das SR, Heroux A, Macbeth MR. Crystal structure of the Entamoeba histolytica RNA lariat debranching enzyme EhDbr1 reveals a catalytic Zn(2+) /Mn(2+) heterobinucleation. FEBS Lett. 2017 Jul;591(13):2003-2010. doi: 10.1002/1873-3468.12677. Epub 2017, Jun 14. PMID:28504306 doi:http://dx.doi.org/10.1002/1873-3468.12677

Student Contributors

SaraKathryn Kalkhoff Camille Gaudet