Assessing multiple conformations of lanthanide binding tags for proteins using sensitive 19F-reporter

2021 ◽  
Author(s):  
Xun-Cheng Su ◽  
Jia-Liang Chen ◽  
Bin Li ◽  
Ben-Guang Chen ◽  
Feng Yang

Quantifying the isomeric species of metal complexes in solution is difficult. 19F NMR herein was used to determine the abundance of isomeric species and dynamic properties of lanthanide binding tags....

Structure ◽  
2014 ◽  
Vol 22 (4) ◽  
pp. 515-525 ◽  
Author(s):  
James M. Aramini ◽  
Keith Hamilton ◽  
Li-Chung Ma ◽  
G.V.T. Swapna ◽  
Paul G. Leonard ◽  
...  

Author(s):  
Wouter Elings ◽  
Aleksandra Chikunova ◽  
Danny B. van Zanten ◽  
Ralphe Drenth ◽  
Misbha Ud Din Ahmad ◽  
...  

The β-lactamase of Mycobacterium tuberculosis, BlaC, is susceptible to inhibition by clavulanic acid. The ability of this enzyme to escape inhibition through mutation was probed using error-prone PCR combined with functional screening in Escherichia coli. The variant that was found to confer most inhibitor resistance, K234R, as well as variant G132N that was found previously, were characterized using X-ray crystallography and NMR relaxation experiments to probe structural and dynamic properties. The G132N mutant exists in solution in two, almost equally populated conformations that exchange with a rate of ca. 88 s−1. The conformational change affects a broad region of the enzyme. The crystal structure reveals that the Asn132 side chain forces the peptide bond between Ser104 and Ile105 in a cis-conformation. The crystal structure suggests multiple conformations for several side chains (e.g. Ser104, Ser130) and a short loop (214-216). In the K234R mutant, the active site dynamics are significantly diminished with respect to the wild type enzyme. These results show that multiple evolutionary routes are available to increase inhibitor resistance in BlaC and that active site dynamics on the millisecond time scale are not required for catalytic function.


2016 ◽  
Vol 7 (3) ◽  
pp. 2222-2228 ◽  
Author(s):  
Zining Zhai ◽  
Qiong Wu ◽  
Wenwen Zheng ◽  
Maili Liu ◽  
Gary J. Pielak ◽  
...  

Multiple conformations of acid chaperone HdeA and their roles in activity.


Author(s):  
R.F. Stump ◽  
J.R. Pfeiffer ◽  
JC. Seagrave ◽  
D. Huskisson ◽  
J.M. Oliver

In RBL-2H3 rat basophilic leukemia cells, antigen binding to cell surface IgE-receptor complexes stimulates the release of inflammatory mediators and initiates a series of membrane and cytoskeletal events including a transformation of the cell surface from a microvillous to a lamellar topography. It is likely that dynamic properties of the IgE receptor contribute to the activation of these responses. Fewtrell and Metzger have established that limited crosslinking of IgE-receptor complexes is essential to trigger secretion. In addition, Baird and colleagues have reported that antigen binding causes a rapid immobilization of IgE-receptor complexes, and we have demonstrated an apparent increase with time in the affinity of IgE-receptor complexes for antigen.


2020 ◽  
Vol 7 (3) ◽  
pp. 786-794 ◽  
Author(s):  
Jingqi Han ◽  
Kin-Man Tang ◽  
Shun-Cheung Cheng ◽  
Chi-On Ng ◽  
Yuen-Kiu Chun ◽  
...  

A new class of luminescent cyclometalated Ir(iii) complexes with readily tunable mechanochromic properties derived from the mechanically induced trans-to-cis isomerization have been developed.


2006 ◽  
Vol 73 ◽  
pp. 109-119 ◽  
Author(s):  
Chris Stockdale ◽  
Michael Bruno ◽  
Helder Ferreira ◽  
Elisa Garcia-Wilson ◽  
Nicola Wiechens ◽  
...  

In the 30 years since the discovery of the nucleosome, our picture of it has come into sharp focus. The recent high-resolution structures have provided a wealth of insight into the function of the nucleosome, but they are inherently static. Our current knowledge of how nucleosomes can be reconfigured dynamically is at a much earlier stage. Here, recent advances in the understanding of chromatin structure and dynamics are highlighted. The ways in which different modes of nucleosome reconfiguration are likely to influence each other are discussed, and some of the factors likely to regulate the dynamic properties of nucleosomes are considered.


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