scholarly journals A novel N-terminal motif of dipeptidyl peptidase-like proteins inactivates KV4.2 channels by a pore-blocking mechanism

Channels ◽  
2009 ◽  
Vol 3 (6) ◽  
pp. 448-461 ◽  
Author(s):  
Henry H. Jerng ◽  
Kevin Dougherty ◽  
Manuel Covarrubias ◽  
Paul J. Pfaffinger
Keyword(s):  
Dipeptidyl Peptidase ◽  
Pore Blocking ◽  
Blocking Mechanism

A new approach to model asphaltene induced permeability damage with emphasis on pore blocking mechanism

2020 ◽  
Vol 184 ◽  
pp. 106512 ◽  
Author(s):  
Marzieh Ghadimi ◽  
Mojtaba Ghaedi ◽  
Mohammad R. Malayeri ◽  
Mohammad J. Amani
Keyword(s):  
New Approach ◽  
Pore Blocking ◽  
Permeability Damage ◽  
Blocking Mechanism

Chloroquine blocks the Kir4.1 channels by an open-pore blocking mechanism

2017 ◽  
Vol 800 ◽  
pp. 40-47 ◽  
Author(s):  
Leticia G. Marmolejo-Murillo ◽  
Iván A. Aréchiga-Figueroa ◽  
Eloy G. Moreno-Galindo ◽  
Ricardo A. Navarro-Polanco ◽  
Aldo A. Rodríguez-Menchaca ◽  
...  
Keyword(s):  
Pore Blocking ◽  
Blocking Mechanism

scholarly journals Mechanism of single- and double-sided inhibition of dual topology fluoride channels by synthetic monobodies

2017 ◽  
Vol 149 (4) ◽  
pp. 511-522 ◽  
Author(s):  
Daniel L. Turman ◽  
Randy B. Stockbridge
Keyword(s):  
Lipid Bilayers ◽  
Symmetry Axis ◽  
Voltage Dependence ◽  
Electrophysiological Study ◽  
Side Chain ◽  
Negative Cooperativity ◽  
Pore Blocking ◽  
Axis Parallel ◽  
Twofold Symmetry Axis ◽  
Blocking Mechanism

The Fluc family of proteins comprises small, electrodiffusive fluoride channels, which prevent accumulation of toxic F− ions in microorganisms. Recent crystal structures have confirmed their unusual architecture, in which a pair of antiparallel subunits convenes to form a dimer with a twofold symmetry axis parallel to the plane of the membrane. These structures have also revealed the interactions between Fluc channels and several different fibronectin domain monobodies that inhibit Fluc-mediated F− currents; in all structures, each channel binds to two monobodies symmetrically, one on either side of the membrane. However, these structures do not reveal the mechanism of monobody inhibition. Moreover, the results appear to diverge from a recent electrophysiological study indicating that monobody binding is negatively cooperative; that is, a bound monobody on one side of a Fluc channel decreases the affinity of an oppositely bound monobody by ∼10-fold. In this study, we reconcile these observations by probing the mechanism of monobody binding and its negative cooperativity using electrophysiological experiments in planar lipid bilayers. Our results indicate that monobody inhibition occurs via a pore-blocking mechanism and that negative cooperativity arises from electrostatic repulsion between the oppositely bound monobodies. A single glutamate residue, on a loop of the monobody that extends into the channel interior, is responsible for negatively cooperative binding. This glutamate side chain also confers voltage dependence and sensitivity to the concentration of trans-F− ion to monobody binding. Neutralization by mutation to glutamine abolishes these electrostatic effects. Monobodies that are amenable to cocrystallization with Fluc channels lack an analogous negatively charged side chain and bind independently to opposite sides of the channel. Thus, this work reveals the source of voltage dependence and negative cooperativity of monobody binding to Fluc channels along with the pore-blocking mechanism.

Studies on pore blocking mechanism and technical feasibility of a hybrid PAC-MF process for reclamation of irrigation water from biotreated POME

2016 ◽  
Vol 51 (12) ◽  
pp. 2047-2061 ◽  
Author(s):  
Mutiu Kolade Amosa ◽  
Mohammed Saedi Jami ◽  
Ma’an Fahmi R. Alkhatib ◽  
Thokozani Majozi
Keyword(s):  
Irrigation Water ◽  
Technical Feasibility ◽  
Pore Blocking ◽  
Blocking Mechanism
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