Structural characterization for N‐terminal domain of caveolin‐1

Abstract

Caveolin‐1 is a principal protein in the plasma membrane microdomains called caveolae. Caveolae play an important role in the transcytosis and pinocytosis. Therefore, caveolin‐1 is most likely to work for the membrane dynamic events. In addition, caveolin‐1 interacts with various signaling molecules. Although caveolin‐1 possesses a variety of physiological functions, its structural properties were little construed. Here we analyzed the structural dynamics of the N‐terminal caveolin‐1 (residues 1–101), in order to better understand the structural properties in terms of its versatile functionality. We first analyzed its oligomeric form using GST‐fused N‐terminal domain, revealing that it equilibrates between a dimer and monomers in a concentration‐dependent manner. The N‐terminal domain of caveolin‐1 was previously found to form a heptamer, so that our data suggest the dimeric form as an intermediate structure for the heptamer formation. Then, we obtained the folding profile, which indicated that AGH2o is about 0.5 ±0.03 kcal/mol. The stability of N‐terminal domain is relatively low, indicating that N‐terminal domain may not be crystalline. Conclusively, the dynamic and flexible structure of N‐terminal domain appears more favorable to maintain the versatile functions of caveolin‐1.