Stabilizing Protein Motifs with a Genetically Encoded Metal-Ion Chelator

作者：Luo Xiaozhou; Wang Tsung Shing Andrew; Zhang Yong; Wang Feng; Schultz Peter G^*

来源：Cell Chemical Biology, 2016, 23(9): 1098-1102.

DOI：10.1016/j.chembiol.2016.08.007

The N-peptide of HIV gp41 forms a trimeric coiled-coil intermediate during host cell-viral fusion. Stable mimics of this coiled coil could potentially serve as HIV vaccine candidates or inhibitors of viral entry. Therefore, a variety of approaches have been investigated to maintain the N-peptide in its trimeric helical conformation. Here, we utilize a genetic method to incorporate the metal chelating noncanonical amino acid (2,20-bipyridin-5-yl) alanine (BpyAla) into IZN17, an established trimeric coiled-coil gp41 model. We demonstrate that BpyAla-IZN17 acquires Fe(II) during expression in Escherichia coli, resulting in the formation of a highly stable IZN17 helical trimer with a T-m > 95 degrees C. Removal of Fe(II) results in a 27 degrees C decrease in thermal stability. Replacement of Fe(II) with Zn(II) also affords a T-m > 90 degrees C. Thus, the genetic introduction of BpyAla into polypeptide provides a straightforward method for stabilizing coiled-coil structural motifs in recombinantly engineered proteins.

• 出版日期2016-9-22