scholarly journals QM/MM simulations identify the determinants of catalytic activity differences between type II dehydroquinase enzymes

2018 ◽  
Vol 16 (24) ◽  
pp. 4443-4455 ◽  
Author(s):  
Emilio Lence ◽  
Marc W. van der Kamp ◽  
Concepción González-Bello ◽  
Adrian J. Mulholland
Keyword(s):  
Catalytic Activity ◽  
Multiscale Simulations ◽  
Specific Interactions ◽  
Type Ii ◽  
Antibiotic Development ◽  
Type Ii Dehydroquinase

Multiscale simulations pinpoint specific interactions responsible for differences in stabilization of key reacting species in two recognized targets for antibiotic development.

scholarly journals 2D/2D type-II Cu2ZnSnS4/Bi2WO6 heterojunctions to promote visible-light-driven photo-Fenton catalytic activity

2020 ◽  
Vol 41 (3) ◽  
pp. 503-513 ◽  
Author(s):  
Li Guo ◽  
Kailai Zhang ◽  
Xuanxuan Han ◽  
Qiang Zhao ◽  
Yuanyuan Zhang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Visible Light ◽  
Type Ii ◽  
Visible Light Driven

scholarly journals The catalytic activity of the endoplasmic reticulum-resident protein microsomal epoxide hydrolase towards carcinogens is retained on inversion of its membrane topology

1996 ◽  
Vol 319 (1) ◽  
pp. 131-136 ◽  
Author(s):  
Thomas FRIEDBERG ◽  
Romy HOLLER ◽  
Bettina LÖLLMANN ◽  
Michael ARAND ◽  
Franz OESCH
Keyword(s):  
Endoplasmic Reticulum ◽  
Catalytic Activity ◽  
Epoxide Hydrolase ◽  
Membrane Topology ◽  
Microsomal Epoxide Hydrolase ◽  
Type I ◽  
Type Ii ◽  
Membrane Orientation ◽  
N Terminus ◽  
Cytochrome P 450

Diol epoxides formed by the sequential action of cytochrome P-450 and the microsomal epoxide hydrolase (mEH) in the endoplasmic reticulum (ER) represent an important class of ultimate carcinogenic metabolites of polycyclic aromatic hydrocarbons. The role of the membrane orientation of cytochrome P-450 and mEH relative to each other in this catalytic cascade is not known. Cytochrome P-450 is known to have a type I topology. According to the algorithm of Hartman, Rapoport and Lodish [(1989) Proc. Natl. Acad. Sci. U.S.A. 86, 5786–5790], which allows the prediction of the membrane topology of proteins, mEH should adopt a type II membrane topology. Experimentally, mEH membrane topology has been disputed. Here we demonstrate that, in contrast with the theoretical prediction, the rat mEH has exclusively a type I membrane topology. Moreover we show that this topology can be inverted without affecting the catalytic activity of mEH. Our conclusions are supported by the observation that two mEH constructs (mEHg1 and mEHg2), containing engineered potential glycosylation sites at two separate locations after the C-terminal site of the membrane anchor, were not glycosylated in fibroblasts. However, changing the net charge at the N-terminus of these engineered mEH proteins by +3 resulted in proteins (++mEHg1 and ++mEHg2) that became glycosylated and consequently had a type II topology. The sensitivity of these glycosylated proteins to endoglycosidase H indicated that, like the native mEH, they are still retained in the ER. The engineered mEH proteins were integrated into membranes as they were resistant to alkaline extraction. Interestingly, an insect mEH with a charge distribution in its N-terminus similar to ++mEHg1 has recently been isolated. This enzyme might well display a type II topology instead of the type I topology of the rat mEH. Importantly, mEHg1, having the natural cytosolic orientation, as well as ++mEHg1, having an artificial luminal orientation, displayed rather similar substrate turnovers for the mutagenic metabolite benzo[a]pyrene 4,5-oxide. To our knowledge this is the first report demonstrating that topological inversion of a protein within the membrane of the ER has only a moderate effect on its enzymic activity, despite differences in folding pathways and redox environments on each side of the membrane. This observation represents an important step in the evaluation of the influence of mEH membrane orientation in the cascade of events leading to the formation of ultimate carcinogenic metabolites, and for studying the general importance of metabolic channelling on the surface of membranes.

scholarly journals Competitive Inhibitors ofHelicobacter pylori Type II Dehydroquinase: Synthesis, Biological Evaluation, and NMR Studies

ChemMedChem ◽  
2008 ◽  
Vol 3 (5) ◽  
pp. 756-770 ◽  
Author(s):  
Cristina Sánchez-Sixto ◽  
Verónica F. V. Prazeres ◽  
Luis Castedo ◽  
Se Won Suh ◽  
Heather Lamb ◽  
...  
Keyword(s):  
Biological Evaluation ◽  
Type Ii ◽  
Nmr Studies ◽  
Competitive Inhibitors ◽  
Type Ii Dehydroquinase

The crystal structure of a type II dehydroquinase fromMycobacterium tuberculosis

1996 ◽  
Vol 52 (a1) ◽  
pp. C115-C115
Author(s):  
D. G. Gourley ◽  
J. R. Coggins ◽  
A. R. Hawkins ◽  
N. W. Isaacs
Keyword(s):  
Crystal Structure ◽  
Type Ii ◽  
Type Ii Dehydroquinase

Crystallization and preliminary X-ray crystallographic analysis of type II dehydroquinase fromHelicobacter pylori

2001 ◽  
Vol 57 (2) ◽  
pp. 279-280 ◽  
Author(s):  
Jae Eun Kwak ◽  
Jae Young Lee ◽  
Byung Woo Han ◽  
Jinho Moon ◽  
Se Hui Sohn ◽  
...  
Keyword(s):  
Crystallographic Analysis ◽  
Type Ii ◽  
X Ray ◽  
Type Ii Dehydroquinase

Rational Design, Synthesis, and Evaluation of Nanomolar Type II Dehydroquinase Inhibitors

ChemMedChem ◽  
2007 ◽  
Vol 2 (7) ◽  
pp. 1015-1029 ◽  
Author(s):  
Richard J. Payne ◽  
Fabienne Peyrot ◽  
Olivier Kerbarh ◽  
Andrew D. Abell ◽  
Chris Abell
Keyword(s):  
Rational Design ◽  
Type Ii ◽  
Design Synthesis ◽  
Type Ii Dehydroquinase

scholarly journals Cloning, sequencing, expression, purification and preliminary characterization of a type II dehydroquinase from Helicobacter pylori

1996 ◽  
Vol 319 (2) ◽  
pp. 559-565 ◽  
Author(s):  
Joanna R BOTTOMLEY ◽  
Christopher L. CLAYTON ◽  
Peter A. CHALK ◽  
Colin KLEANTHOUS
Keyword(s):  
Helicobacter Pylori ◽  
Sequence Data ◽  
Shikimate Pathway ◽  
Cosmid Library ◽  
Type Ii ◽  
Gene Encoding ◽  
Heat Stable ◽  
Plasmid Construct ◽  
H Pylori ◽  
Type Ii Dehydroquinase

A heat-stable dehydroquinase was purified to near homogeneity from a plate-grown suspension of the Gram-negative stomach pathogen Helicobacter pylori, and shown from both its subunit and native molecular masses to be a member of the type II family of dehydroquinases. This was confirmed by N-terminal amino acid sequence data. The gene encoding this activity was isolated following initial identification, by random sequencing of the H. pylori genome, of a 96 bp fragment, the translated sequence of which showed strong identity to a C-terminal region of other type II enzymes. Southern blot analysis of a cosmid library identified several potential clones, one of which complemented an Escherichia coliaroD point mutant strain deficient in host dehydroquinase. The gene encoding the H. pylori type II dehydroquinase (designated aroQ) was sequenced. The translated sequence was identical to the N-terminal sequence obtained directly from the purified protein, and showed strong identity to other members of the type II family of dehydroquinases. The enzyme was readily expressed in E. coli from a plasmid construct from which several milligrams of protein could be isolated, and the molecular mass of the protein was confirmed by electrospray MS. The aroQ gene in H. pylori may function in the central biosynthetic shikimate pathway of this bacterium, thus opening the way for the construction of attenuated strains as potential vaccines as well as offering a new target for selective enzyme inhibition.

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