The characterization of ATPases from the gill of the osteoglossid Osteoglossum bicirrhosum (aruaná)

1978 ◽  
Vol 56 (4) ◽  
pp. 795-800 ◽  
Author(s):  
Thomas W. Moon
Keyword(s):  
Ion Transport ◽  
Divalent Cation ◽  
Binding Sites ◽  
Microsomal Fraction ◽  
Specific Interaction ◽  
Cation Activation ◽  
Multiple Binding Sites ◽  
Monovalent Ions ◽  
Multiple Binding

Gill ATPases of the osteoglossid Osteoglossum bicirrhosum (aruaná) were isolated from the microsomal fraction (Nal pellet) and assayed in the presence of various cations and anions. The presence of Ca2+, Mg2+ (Mn2+), Na+ + K+ (with Mg2+) activated ATP hydrolyses; activation by Ca2+ and Mg2+ was similar and both were inhibited by thiocyanate, but the monovalent ions showed much lower activities. Activities in the presence of these ions were in the range reported for temperate teleosts such as the eel, goldfish, or trout. No HCO3− or NH4+ activation was detected. Apparent Km values for divalent cation activation were well above their respective environmental concentrations, but within the range reported for analogous enzymes of temperate teleosts. There is a specific interaction between Ca2+ and Mg2+ binding to the enzyme, but the results cannot distinguish between the existence of one enzyme with multiple binding sites, or a numberof ion-specific ATPases. These results suggest that the enzyme s assayed in this investigation are only indirectly, if at all, associated with gill ion transport in aruaná.

Molecular localization and characterization of multiple binding sites of organic anion transporting polypeptide 2B1 (OATP2B1) as the mechanism for substrate and modulator dependent drug–drug interaction

MedChemComm ◽  
2016 ◽  
Vol 7 (9) ◽  
pp. 1775-1782 ◽  
Author(s):  
Yusuke Hoshino ◽  
Daichi Fujita ◽  
Takeo Nakanishi ◽  
Ikumi Tamai
Keyword(s):  
Drug Interaction ◽  
Binding Sites ◽  
Organic Anion ◽  
Schematic Model ◽  
Organic Anion Transporting Polypeptide ◽  
Multiple Binding Sites ◽  
Multiple Binding ◽  
Drug Drug Interaction ◽  
The Relationship

Schematic model of the relationship and locations of putative binding sites of substrates and modulators in OATP2B1. Drug–drug interaction and drug–food interaction on OATP2B1 can be predicted by clarification of multiple binding sites.

NMDAR PAMs: Multiple Chemotypes for Multiple Binding Sites

2019 ◽  
Vol 19 (24) ◽  
pp. 2239-2253 ◽  
Author(s):  
Paul J. Goldsmith
Keyword(s):  
Binding Sites ◽  
Receptor Activation ◽  
Research Area ◽  
Allosteric Modulators ◽  
Nonselective Cation Channels ◽  
Multiple Binding Sites ◽  
Multiple Binding ◽  
Excitatory Neurotransmission ◽  
Psychiatric Conditions ◽  
High Level

The N-methyl-D-aspartate receptor (NMDAR) is a member of the ionotropic glutamate receptor (iGluR) family that plays a crucial role in brain signalling and development. NMDARs are nonselective cation channels that are involved with the propagation of excitatory neurotransmission signals with important effects on synaptic plasticity. NMDARs are functionally and structurally complex receptors, they exist as a family of subtypes each with its own unique pharmacological properties. Their implication in a variety of neurological and psychiatric conditions means they have been a focus of research for many decades. Disruption of NMDAR-related signalling is known to adversely affect higherorder cognitive functions (e.g. learning and memory) and the search for molecules that can recover (or even enhance) receptor output is a current strategy for CNS drug discovery. A number of positive allosteric modulators (PAMs) that specifically attempt to overcome NMDAR hypofunction have been discovered. They include various chemotypes that have been found to bind to several different binding sites within the receptor. The heterogeneity of chemotype, binding site and NMDAR subtype provide a broad landscape of ongoing opportunities to uncover new features of NMDAR pharmacology. Research on NMDARs continues to provide novel mechanistic insights into receptor activation and this review will provide a high-level overview of the research area and discuss the various chemical classes of PAMs discovered so far.

Effects of Multiple Binding Sites on Studies of Hydrogen Bonding between Nitroxide Radicals and Solvent Molecules

1993 ◽  
Vol 58 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Imad Al-Bala'a ◽  
Richard D. Bates
Keyword(s):  
Hydrogen Bonding ◽  
Magnetic Resonance ◽  
Binding Site ◽  
Binding Sites ◽  
Hyperfine Coupling Constant ◽  
Hydrogen Donor ◽  
Complex Formation Constants ◽  
Multiple Binding Sites ◽  
Multiple Binding ◽  
Solvent Molecules

The role of more than one binding site on a nitroxide free radical in magnetic resonance determinations of the properties of the complex formed with a hydrogen donor is examined. The expression that relates observed hyperfine couplings in EPR spectra to complex formation constants and concentrations of each species in solution becomes much more complex when multiple binding sites are present, but reduces to a simpler form when binding at the two sites occurs independently and the binding at the non-nitroxide site does not produce significant differences in the hyperfine coupling constant in the complexed radical. Effects on studies of hydrogen bonding between multiple binding site nitroxides and hydrogen donor solvent molecules by other magnetic resonance methods are potentially more extreme.

Creating BHb-imprinted magnetic nanoparticles with multiple binding sites

The Analyst ◽  
2017 ◽  
Vol 142 (2) ◽  
pp. 302-309 ◽  
Author(s):  
Yanxia Li ◽  
Yiting Chen ◽  
Lu Huang ◽  
BenYong Lou ◽  
Guonan Chen
Keyword(s):  
Magnetic Nanoparticles ◽  
Binding Sites ◽  
Multifunctional Nanoparticles ◽  
Multiple Binding Sites ◽  
Multiple Binding

A kind of protein imprinted over magnetic Fe3O4@Au multifunctional nanoparticles (NPs) with multiple binding sites was synthesized and investigated.

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