Sandbox Reserved 918: Difference between revisions

Though DPP IV's primary function is as a hydrolase, it also serves as a [http://en.wikipedia.org/wiki/Transmembrane_protein transmembrane] glycoprotein on the surface of cells. A specific domain, the <scene name='57/573132/1x70_8bladed/2'>8-bladed β-propeller domain</scene>, works in binding the most well known DPP IV ligand, [http://en.wikipedia.org/wiki/Adenosine_deaminase adenosine deaminase] (or ADA). Unlike some other leucocyte surface molecules, (which have a 7-bladed β-propeller) the β-propeller of DPP IV is unique in that its 8 blades make it more disordered.<ref name="Gorrell"/> ADA can bind to either the monomer or dimer of DPP IV because each monomer contains the 8-bladed propeller domain. ADA actually binds to the lower side of this domain, with three important residues being <scene name='57/573132/1x70_8bladed_lower/2'>Val341, Thr440, and Lys441</scene>, at the fourth and fifth propeller. Adenosine deaminase works to deaminate adenosine into [http://en.wikipedia.org/wiki/Inosine inosine], an important function in [http://en.wikipedia.org/wiki/Purine_metabolism purine metabolism]<ref name="regpeps"/>, however it's most important role in humans deals with the immune system.<ref name="Gorrell"/> ADA is a well understood enzyme that is highly conserved across numerous species in the body<ref name="Gorrell"/>, yet it's binding to DPP IV is not completely understood, especially the biological importance of the interaction. One theory is that binding ADA to the DPP IV glycoprotein inhibits its catalytic function, increasing the concentration of extracellular adenosine which plays a role in [http://en.wikipedia.org/wiki/T_cell T-cell] proliferation. <ref name="Gorrell"/>