Copper(II) complexes of sterically hindered phenolate ligands as structural models for the active site in galactose oxidase and glyoxal oxidase: X-ray crystal structure and spectral and redox properties

2001 ◽  
Vol 324 (1-2) ◽  
pp. 241-251 ◽  
Author(s):  
Mathrubootham Vaidyanathan ◽  
Mallayan Palaniandavar ◽  
R. Srinivasa Gopalan
Keyword(s):  
Crystal Structure ◽  
Active Site ◽  
Structural Models ◽  
Redox Properties ◽  
Galactose Oxidase ◽  
X Ray ◽  
Phenolate Ligands ◽  
Sterically Hindered ◽  
Glyoxal Oxidase

Copper(II) Complexes with Unusual Axial Phenolate Coordination as Structural Models for the Active Site in Galactose Oxidase:  X-ray Crystal Structures and Spectral and Redox Properties of [Cu(bpnp)X] Complexes

1998 ◽  
Vol 37 (25) ◽  
pp. 6418-6427 ◽  
Author(s):  
Mathrubootham Vaidyanathan ◽  
Rathinam Viswanathan ◽  
Mallayan Palaniandavar ◽  
T. Balasubramanian ◽  
P. Prabhaharan ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Active Site ◽  
Structural Models ◽  
Redox Properties ◽  
Galactose Oxidase ◽  
X Ray

scholarly journals Crystal Structure, Exogenous Ligand Binding, and Redox Properties of an Engineered Diiron Active Site in a Bacterial Hemerythrin

2013 ◽  
Vol 52 (22) ◽  
pp. 13014-13020 ◽  
Author(s):  
Yasunori Okamoto ◽  
Akira Onoda ◽  
Hiroshi Sugimoto ◽  
Yu Takano ◽  
Shun Hirota ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ligand Binding ◽  
Active Site ◽  
Redox Properties ◽  
Exogenous Ligand

ChemInform Abstract: Synthesis, X-Ray Crystal Structure, and Multistage Redox Properties of a Severely-Distorted Tetrathiafulvalene Donor.

ChemInform ◽  
2010 ◽  
Vol 23 (26) ◽  
pp. no-no
Author(s):  
M. R. BRYCE ◽  
M. A. COFFIN ◽  
M. B. HURSTHOUSE ◽  
A. I. KARAULOV ◽  
K. MUELLEN ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Redox Properties ◽  
X Ray

Crystal Structure, Spectroscopic and Redox Properties of Copper(II) Bis{2-[(2,6-dimethylphenyl)iminomethyl-3-methoxyphenolate]}

2007 ◽  
Vol 62 (9) ◽  
pp. 1133-1138 ◽  
Author(s):  
Veli T. Kasumov ◽  
Ibrahim Uçar ◽  
Ahmet Bulut ◽  
Fevzi Kösal
Keyword(s):  
Crystal Structure ◽  
Title Complex ◽  
Redox Properties ◽  
Orthorhombic Space Group ◽  
Long Distance ◽  
X Ray ◽  
X Ray Crystallography ◽  
Square Planar ◽  
Planar Molecules ◽  
Exchange Interaction Parameter

The coordination chemistry of N-(2,6-di-methylphenyl)-2-hydroxy-3-methoxybenzaldimine (1) with Cu(II) has been investigated by X-ray crystallography, electronic and EPR spectroscopies, as well as by electro- and magnetochemistry. The title complex 2 crystallizes in the orthorhombic space group P212121 (a = 8.1538, b = 17.7466, c =19.8507 Å). The mononuclear square-planar molecules 2 featuring trans-N2O2 coordination are connected via weak intermolecular C-H· · ·π interactions into infinite chains parallel to the a axis. Although the intermolecular Cu· · ·Cu separations within individual chains and between chains are very long (8.154 and 9.726 Å ), the exchange interaction parameter G = 2.03 < 4, estimated from solid state EPR spectra, suggests the existence of long-distance superexchange pathways between adjacent Cu(II) centers. The electronic and electrochemical features of the compound are also discussed.

scholarly journals Crystal structure of a pyridoxal 5′-phosphate-dependent aspartate racemase derived from the bivalve mollusc Scapharca broughtonii

2017 ◽  
Vol 73 (12) ◽  
pp. 651-656 ◽  
Author(s):  
Taichi Mizobuchi ◽  
Risako Nonaka ◽  
Motoki Yoshimura ◽  
Katsumasa Abe ◽  
Shouji Takahashi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Binding Site ◽  
Active Site ◽  
Metal Binding ◽  
Bivalve Mollusc ◽  
Active Site Residues ◽  
X Ray ◽  
Aspartate Racemase ◽  
Scapharca Broughtonii

Aspartate racemase (AspR) is a pyridoxal 5′-phosphate (PLP)-dependent enzyme that is responsible for D-aspartate biosynthesis in vivo. To the best of our knowledge, this is the first study to report an X-ray crystal structure of a PLP-dependent AspR, which was resolved at 1.90 Å resolution. The AspR derived from the bivalve mollusc Scapharca broughtonii (SbAspR) is a type II PLP-dependent enzyme that is similar to serine racemase (SR) in that SbAspR catalyzes both racemization and dehydration. Structural comparison of SbAspR and SR shows a similar arrangement of the active-site residues and nucleotide-binding site, but a different orientation of the metal-binding site. Superposition of the structures of SbAspR and of rat SR bound to the inhibitor malonate reveals that Arg140 recognizes the β-carboxyl group of the substrate aspartate in SbAspR. It is hypothesized that the aromatic proline interaction between the domains, which favours the closed form of SbAspR, influences the arrangement of Arg140 at the active site.

Difference in Conformation of Virginiamycin M1 in Chloroform and Bound Form in the 50S Ribosome or Streptogramin Acetyltransferase

2004 ◽  
Vol 57 (5) ◽  
pp. 415 ◽  
Author(s):  
Jason Dang ◽  
B. Mikael Bergdahl ◽  
Frances Separovic ◽  
Robert T. C. Brownlee ◽  
Robert P. Metzger
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Active Site ◽  
Major Change ◽  
X Ray ◽  
Binding Process ◽  
High Resolution Nmr ◽  
Virginiamycin M1

The conformation of virginiamycin M1 (VM1) in chloroform, determined by high-resolution NMR experiments, differs significantly from that of the X-ray crystal structure of VM1 bound to the 50S ribosome and to the active site of a streptogramin acetyltransferase enzyme. This implies that the binding process to these entities causes a major change in VM1 conformation.

1,1-Organoboration of Sterically Hindered Tetra-l-alkynylsilanes and the Crystal Structure of Tetrakis[1-(3,3-dimethyl)butynyl]silane

1996 ◽  
Vol 51 (9) ◽  
pp. 1320-1324 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Heidi E. Maisei ◽  
Jürgen Süß ◽  
Wolfgang Milius
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Ring System ◽  
Large Excess ◽  
Space Group ◽  
X Ray ◽  
Kinetically Controlled ◽  
Sterically Hindered ◽  
Boiling Toluene

Tetra-1-alkynylsilanes, Si(C≡CR1)4 with R1 = tBu (1) and SiMe3 (2) react with triethylborane, Et3B. by intermolecular 1,1-ethyloboration followed by intramolecular 1,1-vinyloboration, to give the substituted siloles 3 and 5 with two R1C≡C groups linked to silicon. The formation of 5 (R1 = SiMe3) requires exactly one equivalent of Et3B, whereas 3 (R1 = tBu) is formed after ≈ 20 d in boiling toluene in the presence of a large excess of Et3B, and the remaining tBu -C ≡ C groups in 3 do not react with Et3B. The 1,1-organoboration of 2 using one equivalent of 9-ethyl-9-borabicyclo[3.3.1]nonane, Et-9-BBN, proceeds similar to the Et3B-reaction, to give mainly the silole derivative 6, in which the bicyclic ring system is enlarged by two carbon atoms. This product is the result of a kinetically controlled reaction. The single crystal X-ray analysis of 1 has been carried out (space group Pnma; a = 990.0(2), b = 1668.0(3), c = 1479.0(3) pm), and its crystal structure is com pared with that of the corresponding tin compound 1 (Sn).

Influence of the presence of the heme cofactor on the JK-loop structure in indoleamine 2,3-dioxygenase 1

2020 ◽  
Vol 76 (12) ◽  
pp. 1211-1221
Author(s):  
Manon Mirgaux ◽  
Laurence Leherte ◽  
Johan Wouters
Keyword(s):  
Crystal Structure ◽  
Cancer Research ◽  
Active Site ◽  
Loop Structure ◽  
X Ray Diffraction ◽  
Dynamic Information ◽  
X Ray ◽  
Indoleamine 2,3 Dioxygenase ◽  
First Time ◽  
Heme Cofactor

Indoleamine 2,3-dioxygenase 1 has sparked interest as an immunotherapeutic target in cancer research. Its structure includes a loop, named the JK-loop, that controls the orientation of the substrate or inhibitor within the active site. However, little has been reported about the crystal structure of this loop. In the present work, the conformation of the JK-loop is determined for the first time in the presence of the heme cofactor in the active site through X-ray diffraction experiments (2.44 Å resolution). Molecular-dynamics trajectories were also obtained to provide dynamic information about the loop according to the presence of cofactor. This new structural and dynamic information highlights the importance of the JK-loop in confining the labile heme cofactor to the active site.

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