• Study in vitro regulation of Rap1b cell signaling mechanisms
• Serves as a substrate for Rap1b GEF assays and drug screens

Rap1b is a small GTP-binding protein belonging to the Ras family that plays a critical role in regulating cell adhesion, cell–cell junction formation, and intracellular signaling. It is involved in diverse cellular processes, including cytoskeletal reorganization and integrin-mediated signaling, making it essential for cell migration and tissue integrity.

Wild-type human Rap1b protein is produced in a bacterial expression system.

• Protein tag: N-terminal His tag for purification
• Molecular weight: approximate mwt 23-25 kDa
• Formulation: supplied as a lyophilized powder
• Composition: when resuspended to 5 mg/ml, the buffer composition is: 2 mM Tris, pH 7.6, 0.5 mM MgCl2, 0.5% (w/v) sucrose, and 0.1% (w/v) dextran

Protein purity is assessed by scanning densitometry of Coomassie Blue-stained protein on a 4-20% polyacrylamide gel. Purity was determined to be ≥88% pure.

The biological activity of Rap1b is measured by its ability to exchange GDP and GTP. In the assay, EDTA induces a conformational change in His-Ras that mimics GEF activity—using the Rho GEF Exchange Assay Kit Cat. # BK100 quality control confirms that 40 mM EDTA doubles the exchange rate (Vmax) of Rap1b.