scholarly journals A Pivotal Heme-transfer Reaction Intermediate in CytochromecBiogenesis

2011 ◽  
Vol 287 (4) ◽  
pp. 2342-2352 ◽  
Author(s):  
Despoina A. I. Mavridou ◽  
Julie M. Stevens ◽  
Leonie Mönkemeyer ◽  
Oliver Daltrop ◽  
Katalin di Gleria ◽  
...  
Keyword(s):  
Transfer Reaction ◽  
Reaction Intermediate ◽  
Heme Transfer

Structural basis for the heme transfer reaction in heme uptake machinery from Corynebacteria

2019 ◽  
Vol 55 (92) ◽  
pp. 13864-13867
Author(s):  
Norifumi Muraki ◽  
Chihiro Kitatsuji ◽  
Yasunori Okamoto ◽  
Takeshi Uchida ◽  
Koichiro Ishimori ◽  
...  
Keyword(s):  
Transfer Reaction ◽  
Structural Basis ◽  
Heme Binding ◽  
Heme Uptake ◽  
Heme Transfer

The CR domains in HtaA and HtaB are responsible for heme binding/transport in the heme-uptake machinery in Corynebacteria.

scholarly journals Structure of Amidase fromPseudomonas aeruginosaShowing a Trapped Acyl Transfer Reaction Intermediate State

2007 ◽  
Vol 282 (27) ◽  
pp. 19598-19605 ◽  
Author(s):  
Jorge Andrade ◽  
Amin Karmali ◽  
Maria A. Carrondo ◽  
Carlos Frazão
Keyword(s):  
Intermediate State ◽  
Transfer Reaction ◽  
Acyl Transfer ◽  
Reaction Intermediate ◽  
Acyl Transfer Reaction

Sulfamides Direct Radical-Mediated Chlorination of Aliphatic C–H Bonds

2019 ◽  
Author(s):  
Melanie Short ◽  
Mina Shehata ◽  
Matthew Sanders ◽  
Jennifer Roizen
Keyword(s):  
Hydrogen Atom ◽  
Transfer Reaction ◽  
Hydrogen Atom Transfer ◽  
Chain Propagation ◽  
Propagation Mechanism ◽  
Atom Transfer ◽  
Radical Chain ◽  
Radical Intermediates ◽  
Transfer Processes ◽  
Unusual Position

Sulfamides guide intermolecular chlorine transfer to gamma-C(sp<sup>3</sup>) centers. This unusual position-selectivity arises because accessed sulfamidyl radical intermediates engage in otherwise rare 1,6-hydrogen-atom transfer processes. The disclosed chlorine-transfer reaction relies on a light-initiated radical chain-propagation mechanism to oxidize C(sp<sup>3</sup>)-H bonds.

Rationalizing the pH-Activity Response for Escherichia Coli’s Glycinamide Ribonucleotidetransformylase Through Computational Methods

2019 ◽  
Author(s):  
Adrian Roitberg ◽  
Pancham Lal Gupta
Keyword(s):  
Transfer Reaction ◽  
Catalytic Mechanism ◽  
Ph Dependence ◽  
Ph Effects ◽  
Dependent Manner ◽  
E Coli ◽  
Gar Tfase ◽  
Activity Curve ◽  
Ph Dependent ◽  
Formyl Transfer

<div>Human Glycinamide ribonucleotide transformylase (GAR Tfase), a regulatory enzyme in the de novo purine biosynthesis pathway, has been established as an anti-cancer target. GAR Tfase catalyzes the formyl transfer reaction from the folate cofactor to the GAR ligand. In the present work, we study E. coli GAR Tfase, which has high sequence similarity with the human GAR Tfase with most functional residues conserved. E. coli GAR Tfase exhibits structural changes and the binding of ligands that varies with pH which leads to change the rate of the formyl transfer reaction in a pH-dependent manner. Thus, the inclusion of pH becomes essential for the study of its catalytic mechanism. Experimentally, the pH-dependence of the kinetic parameter kcat is measured to evaluate the pH-range of enzymatic activity. However, insufficient information about residues governing the pH-effects on the catalytic activity leads to ambiguous assignments of the general acid and base catalysts and consequently its catalytic mechanism. In the present work, we use pH-replica exchange molecular dynamics (pH-REMD) simulations to study the effects of pH on E. coli GAR Tfase enzyme. We identify the titratable residues governing the pH-dependent conformational changes in the system. Furthermore, we filter out the protonation states which are essential in maintaining the structural integrity, keeping the ligands bound and assisting the catalysis. We reproduce the experimental pH-activity curve by computing the population of key protonation states. Moreover, we provide a detailed description of residues governing the acidic and basic limbs of the pH-activity curve.</div>

Sulfamides Direct Radical-Mediated Chlorination of Aliphatic C–H Bonds

2019 ◽  
Author(s):  
Melanie Short ◽  
Mina Shehata ◽  
Matthew Sanders ◽  
Jennifer Roizen
Keyword(s):  
Hydrogen Atom ◽  
Transfer Reaction ◽  
Hydrogen Atom Transfer ◽  
Chain Propagation ◽  
Propagation Mechanism ◽  
Atom Transfer ◽  
Radical Chain ◽  
Radical Intermediates ◽  
Transfer Processes ◽  
Unusual Position

Sulfamides guide intermolecular chlorine transfer to gamma-C(sp<sup>3</sup>) centers. This unusual position-selectivity arises because accessed sulfamidyl radical intermediates engage in otherwise rare 1,6-hydrogen-atom transfer processes. The disclosed chlorine-transfer reaction relies on a light-initiated radical chain-propagation mechanism to oxidize C(sp<sup>3</sup>)-H bonds.

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