Structural Insights and the Surprisingly Low Mechanical Stability of the Au-S Bond in the Gold-Specific Protein GolB
Wei, W., Sun, Y., Zhu, M., Liu, X., Sun, P., Wang, F., Gui, Q., Meng, W., Cao, Y., Zhao, J.(2015) J Am Chem Soc 137: 15358-15361
- PubMed: 26636614 
- DOI: https://doi.org/10.1021/jacs.5b09895
- Primary Citation of Related Structures:  
4Y2I, 4Y2K, 4Y2M - PubMed Abstract: 
The coordination bond between gold and sulfur (Au-S) has been widely studied and utilized in many fields. However, detailed investigations on the basic nature of this bond are still lacking. A gold-specific binding protein, GolB, was recently identified, providing a unique opportunity for the study of the Au-S bond at the molecular level. We probed the mechanical strength of the gold-sulfur bond in GolB using single-molecule force spectroscopy. We measured the rupture force of the Au-S bond to be 165 pN, much lower than Au-S bonds measured on different gold surfaces (∼1000 pN). We further solved the structures of apo-GolB and Au(I)-GolB complex using X-ray crystallography. These structures showed that the average Au-S bond length in GolB is much longer than the reported average value of Au-S bonds. Our results highlight the dramatic influence of the unique biological environment on the stability and strength of metal coordination bonds in proteins.
Organizational Affiliation: 
Elias James Corey Institute of Biomedical Research, Wuxi Biortus Biosciences Co., Ltd , Jiangyin, 214437, China.