Anionic Catalytic Site
Anionic Catalytic Site - Related Videos
08:56
Catalytic Reactor: Hydrogenation of Ethylene
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2023
Source: Kerry M. Dooley and Michael G. Benton, Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA The hydrogenation of ethylene (C2H4) to ethane (C2H6) has often been studied as a model reduction reaction in characterizing new metal catalysts.1-2 While supported nickel is not the most active metal catalyst for this reaction, it is active enough that reaction can take place at < 200°C. The reaction typically involves adsorbed, dissociated hydrogen (H2) reacting...
09:46
Catalytic Scavenging of Plant Reactive Oxygen Species In Vivo by Anionic Cerium Oxide Nanoparticles
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Cited by 24 •
2018
Here, we present a protocol for the synthesis and characterization of cerium oxide nanoparticles (nanoceria) for ROS (reactive oxygen species) scavenging in vivo, nanoceria imaging in plant tissues by confocal microscopy, and in vivo monitoring of nanoceria ROS scavenging by confocal microscopy.
02:38
Anion Exchange Resin–Based Detection of Viruses from Bioaerosols
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2026
Source: Schaeffer, J. W., Chandler, et al. Detection of Viruses from Bioaerosols Using Anion Exchange Resin. J. Vis. Exp. (2018).This video demonstrates the detection of viruses from bioaerosols using an anion exchange resin. A liquid impinger containing the resin is used to capture viruses from the air. The resin is collected and treated with a virus lysis buffer containing carrier RNA. The lysate is transferred to a microcentrifuge tube for viral RNA isolation, followed by qRT-PCR to amplify...
01:07
Catalytically Perfect Enzymes
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2023
The theory of catalytically perfect enzymes was first proposed by W.J. Albery and J. R. Knowles in 1976. These enzymes catalyze biochemical reactions at high-speed. Their catalytic efficiency values range from 108-109 M-1s-1. These enzymes are also called 'diffusion-controlled' as the only rate-limiting step in the catalysis is that of the substrate diffusion into the active site. Examples include triose phosphate isomerase, fumarase, and superoxide dismutase. Most enzymes achieve catalytic...
01:19
Turnover Number and Catalytic Efficiency
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2023
The turnover number of an enzyme is the maximum number of substrate molecules it can transform per unit time. Turnover numbers for most enzymes range from 1 to 1000 molecules per second. Catalase has the known highest turnover number, capable of converting up to 2.8×106 molecules of hydrogen peroxide into water and oxygen per second. Lysozyme has the lowest known turnover number of half a molecule per second. Chymotrypsin is a pancreatic enzyme that breaks down proteins during digestion. The...
FAQs
Electrostatic attraction favors entry and retention of positively charged substrates, ligands, or drugs within the site. This initial interaction can increase the likelihood that the molecule reaches a productive orientation rather than binding randomly. Consequently, the site’s charge contributes to molecular recognition and helps explain differences in binding affinity among cationic compounds.
Surrounding residues position the bound molecule and create the local arrangement needed for subsequent chemical steps. Their influence may extend to bond cleavage or proton transfer, so binding and catalysis are connected but not identical processes. A compound can therefore interact electrostatically with the site while its final effect also depends on how residues orient it.
The same region can support two related stages of protein function: recognition of a positively charged molecule and progression toward a chemical reaction. Attraction helps bring the molecule into the site, whereas residue-dependent positioning may enable bond cleavage or proton transfer. This distinction is important when interpreting why strong binding does not alone describe the complete mechanism.
Characterization can connect a drug’s molecular interactions with measurable pharmacological properties such as potency and binding affinity. It can also clarify whether the compound acts through recognition of the site, interference with catalysis, or both. These relationships help interpret mechanism of action and provide a basis for comparing compounds with different effects on the same protein.
In cholinesterases, the site helps explain how positively charged neurotransmitters and inhibitors interact with the enzyme. Examining their attraction and positioning can clarify why particular compounds bind, how inhibitors affect enzyme function, and how those interactions relate to pharmacological activity. This context supports interpretation of cholinesterase inhibitor potency and mechanism of action.
Alterations in charge or three-dimensional site structure can change how effectively a cationic drug is attracted, retained, or positioned. Those changes may modify binding affinity, catalytic interactions, and ultimately pharmacological response. Evaluating such effects is therefore relevant to explaining variability in drug action and to designing compounds with greater selectivity for a target protein.