Noncovalent structural models for the Asp-His dyad in the active site of serine proteases and for solid-state switching of protonation states: crystal structure of the associates of 1,1'-binaphthyl-2,2'-dicarboxylic acid with imidazole in dihydrated and in anhydrous forms

1986 ◽  
Vol 108 (6) ◽  
pp. 1275-1281 ◽  
Author(s):  
Matyas. Czugler ◽  
Janos G. Angyan ◽  
Gabor. Naray-Szabo ◽  
Edwin. Weber
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Dicarboxylic Acid ◽  
Active Site ◽  
Serine Proteases ◽  
Structural Models ◽  
State Switching

scholarly journals Synthesis and crystal structure of 1,1′-bis{[4-(pyridin-2-yl)-1,2,3-triazol-1-yl]methyl}ferrocene, and its complexation with CuI

2020 ◽  
Vol 76 (10) ◽  
pp. 1582-1586
Author(s):  
Uttam R. Pokharel ◽  
Aaron P. Naquin ◽  
Connor P. Brochon ◽  
Frank R. Fronczek
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Dicarboxylic Acid ◽  
Title Compound ◽  
Inversion Center ◽  
Dimeric Complex ◽  
Reaction Sequence ◽  
Synthesis And Crystal Structure ◽  
Π Interactions

The title compound, [Fe(C13H11N4)2], was synthesized starting from 1,1′-ferrocenedicarboxylic acid in a three-step reaction sequence. The dicarboxylic acid was reduced to 1,1′-ferrocenedimethanol using LiAlH4 and subsequently converted to 1,1′-bis(azidomethyl)ferrocene in the presence of NaN3. The diazide was treated with 2-ethynylpyridine under `click' conditions to give the title compound in 75% yield. The FeII center lies on an inversion center in the crystal. The two pyridyltriazole wings are oriented in an anti conformation and positioned exo from the FeII center. In the solid state, the molecules interact by C—H...N, C—H...π, and π–π interactions. The complexation of the ligand with [Cu(CH3CN)4](PF6) gives a tetranuclear dimeric complex.

Ruthenium(II) Complexes Bearing Thioether-Appended α- Iminopyridine Ligands: Arene Precursors Permit Access to K2-N,N and K3-N,N,S Complexes

2019 ◽  
Author(s):  
Victoria A. Ternes ◽  
Hannah A. Morgan ◽  
Austin P. Lanquist ◽  
Michael P. Murray ◽  
Bradley Wile
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Strong Field ◽  
Active Role ◽  
Binding Mode ◽  
Phenethyl Alcohol ◽  
Ru Complexes

Herein we report the preparation of a series of Ru(II) complexes featuring alpha-iminopyridine ligands bearing thioether functionality (NNS<sup>R</sup>, where R = Me, CH<sub>2</sub>Ph, Ph). Metallation using (<i>p</i> cymene)RuCl dimer permits access to (k<sup>2</sup>-N,N)Ru complexes in which the thioether moiety remains uncoordinated. In the presence of a strong field ligand such as acetonitrile or triphenylphosphine, the p-cymene moiety is displaced, and the ligand adopts a k<sup>3</sup>-N,N,S binding mode. These complexes are characterized using a combination of solution and solid state methods, including the crystal structure of [(NNS<sup>Me</sup>)Ru(NCMe)<sub>2</sub>Cl]Cl. The k<sup>2</sup>-N,N Ru(II) complexes are shown to serve as efficient precatalysts for the oxidation of sec-phenethyl alcohol at 5 mol% loadings, using a variety of external oxidants and solvents. The complex bearing an S-Ph donor was found to be the most active of those surveyed, suggesting that the thioether donor plays an active role in catalyst speciation for this transformation.

Crystal structure of tetraoxa[4]peristylane: Novel CH…O mediated architecture in the solid state

1999 ◽  
Vol 40 (12) ◽  
pp. 2417-2420 ◽  
Author(s):  
Goverdhan Mehta ◽  
Ramdas Vidya ◽  
Kailasam Venkatesan
Keyword(s):  
Crystal Structure ◽  
Solid State

scholarly journals Serine protease dynamics revealed by NMR analysis of the thrombin-thrombomodulin complex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Riley B. Peacock ◽  
Taylor McGrann ◽  
Marco Tonelli ◽  
Elizabeth A. Komives
Keyword(s):  
Active Site ◽  
Serine Proteases ◽  
Protein C ◽  
Catalytic Mechanism ◽  
Bond Cleavage ◽  
Peptide Bond ◽  
Peptide Bond Cleavage ◽  
Exchange Mass Spectrometry ◽  
Catalytically Active ◽  
Hydrogen Deuterium

AbstractSerine proteases catalyze a multi-step covalent catalytic mechanism of peptide bond cleavage. It has long been assumed that serine proteases including thrombin carry-out catalysis without significant conformational rearrangement of their stable two-β-barrel structure. We present nuclear magnetic resonance (NMR) and hydrogen deuterium exchange mass spectrometry (HDX-MS) experiments on the thrombin-thrombomodulin (TM) complex. Thrombin promotes procoagulative fibrinogen cleavage when fibrinogen engages both the anion binding exosite 1 (ABE1) and the active site. It is thought that TM promotes cleavage of protein C by engaging ABE1 in a similar manner as fibrinogen. Thus, the thrombin-TM complex may represent the catalytically active, ABE1-engaged thrombin. Compared to apo- and active site inhibited-thrombin, we show that thrombin-TM has reduced μs-ms dynamics in the substrate binding (S1) pocket consistent with its known acceleration of protein C binding. Thrombin-TM has increased μs-ms dynamics in a β-strand connecting the TM binding site to the catalytic aspartate. Finally, thrombin-TM had doublet peaks indicative of dynamics that are slow on the NMR timescale in residues along the interface between the two β-barrels. Such dynamics may be responsible for facilitating the N-terminal product release and water molecule entry that are required for hydrolysis of the acyl-enzyme intermediate.

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