Cysteine-Mediated Dynamic Hydrogen-Bonding Network in the Active Site of Pin1

Biochemistry ◽  
2014 ◽  
Vol 53 (23) ◽  
pp. 3839-3850 ◽  
Author(s):  
Arghya Barman ◽  
Donald Hamelberg
Biomimetics ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 66
Author(s):  
Park ◽  
Lee

Zinc complexes were synthesized as catalysts that mimic the ability of carbonic anhydrase (CA) for the CO2 hydration reaction (H2O + CO2 → H+ + HCO3-). For these complexes, a tris(2-pyridylmethyl)amine (TPA) ligand mimicking only the active site, and a 6-((bis(pyridin-2-ylmethyl)amino)methyl)pyridin-2-ol (TPA-OH) ligand mimicking the hydrogen-bonding network of the secondary coordination sphere of CA were used. Potentiometric pH titration was used to determine the deprotonation ability of the Zn complexes, and their pKa values were found to be 8.0 and 6.8, respectively. Stopped-flow spectrophotometry was used to confirm the CO2 hydration rate. The rate constants were measured to be 648.4 and 730.6 M-1s-1, respectively. The low pKa value was attributed to the hydrogen-bonding network of the secondary coordination sphere of the catalyst that mimics the behavior of CA, and this was found to increase the CO2 hydration rate of the catalyst.


Biochemistry ◽  
2016 ◽  
Vol 55 (27) ◽  
pp. 3834-3846 ◽  
Author(s):  
Melek N. Ucisik ◽  
Philip C. Bevilacqua ◽  
Sharon Hammes-Schiffer

1992 ◽  
Vol 282 (1) ◽  
pp. 189-195 ◽  
Author(s):  
J Lamotte-Brasseur ◽  
F Jacob-Dubuisson ◽  
G Dive ◽  
J M Frère ◽  
J M Ghuysen

In previous studies, several amino acids of the active site of class A beta-lactamases have been modified by site-directed mutagenesis. On the basis of the catalytic mechanism proposed for the Streptomyces albus G beta-lactamase [Lamotte-Brasseur, Dive, Dideberg, Charlier, Frère & Ghuysen (1991) Biochem. J. 279, 213-221], the influence that these mutations exert on the hydrogen-bonding network of the active site has been analysed by molecular mechanics. The results satisfactorily explain the effects of the mutations on the kinetic parameters of the enzyme's activity towards a set of substrates. The present study also shows that, upon binding a properly structured beta-lactam compound, the impaired cavity of a mutant enzyme can readopt a functional hydrogen-bonding-network configuration.


2015 ◽  
Vol 111 ◽  
pp. 9-15 ◽  
Author(s):  
Jin Zeng ◽  
Yuan Zhao ◽  
Wei Li ◽  
Xiangshi Tan ◽  
Ge-Bo Wen ◽  
...  

Biochemistry ◽  
2012 ◽  
Vol 51 (44) ◽  
pp. 8802-8813 ◽  
Author(s):  
Louisa Reissig ◽  
Tatsuya Iwata ◽  
Takashi Kikukawa ◽  
Makoto Demura ◽  
Naoki Kamo ◽  
...  

2020 ◽  
Vol 21 (20) ◽  
pp. 7515
Author(s):  
Chih-Hsuan Lai ◽  
Co-Chih Chang ◽  
Huai-Chia Chuang ◽  
Tse-Hua Tan ◽  
Ping-Chiang Lyu

Cysteine-based protein tyrosine phosphatases (Cys-based PTPs) perform dephosphorylation to regulate signaling pathways in cellular responses. The hydrogen bonding network in their active site plays an important conformational role and supports the phosphatase activity. Nearly half of dual-specificity phosphatases (DUSPs) use three conserved residues, including aspartate in the D-loop, serine in the P-loop, and asparagine in the N-loop, to form the hydrogen bonding network, the D-, P-, N-triloop interaction (DPN–triloop interaction). In this study, DUSP22 is used to investigate the importance of the DPN–triloop interaction in active site formation. Alanine mutations and somatic mutations of the conserved residues, D57, S93, and N128 substantially decrease catalytic efficiency (kcat/KM) by more than 102-fold. Structural studies by NMR and crystallography reveal that each residue can perturb the three loops and induce conformational changes, indicating that the hydrogen bonding network aligns the residues in the correct positions for substrate interaction and catalysis. Studying the DPN–triloop interaction reveals the mechanism maintaining phosphatase activity in N-loop-containing PTPs and provides a foundation for further investigation of active site formation in different members of this protein class.


2005 ◽  
Vol 61 (11) ◽  
pp. o625-o627
Author(s):  
Janusz Zachara ◽  
Izabela D. Madura ◽  
Andrzej Zimniak ◽  
Irena Oszczapowicz ◽  
Iwona Chrobak

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