Related Experiment Video
Updated: Jul 31, 2026
19:16
The Importance of Correct Protein Concentration for Kinetics and Affinity Determination in Structure-function Analysis
Published on: March 17, 2010
The lock-in phase in the urotropine-sebacic acid system
M Gardon1, A Schönleber, G Chapuis
1Institut de Cristallographie, Université de Lausanne, BSP Dorigny, CH-1015 Lausanne, Switzerland.
Summary
The study of the 1,10-decanedioic acid-urotropine system at low temperature reveals a clear acid character in the end-groups. This finding addresses the acid-carboxylate controversy in urotropine-alkanedioic acid systems.
Area of Science:
- Crystallography
- Materials Science
- Chemical Physics
Background:
- The acid-carboxylate controversy in urotropine-alkanedioic acid systems remains a significant topic.
- Understanding the structural behavior of these systems is crucial for materials science applications.
Purpose of the Study:
- To investigate the structural properties of the 1,10-decanedioic acid-urotropine (1/1) system.
- To provide insights into the acid-carboxylate controversy within urotropine-alkanedioic acid systems.
Main Methods:
- Single-crystal X-ray diffraction at 215 K.
- Analysis of a commensurate modulated phase.
Main Results:
- The crystal structure of the 1,10-decanedioic acid-urotropine (1/1) system was determined at 215 K.
- All chain end-groups exhibited a distinct acid character.
- The asymmetric unit contained two molecules of diacid and two molecules of urotropine.
- Chain packing analysis suggested a potential order parameter for the lock-in transition.
Conclusions:
- The study resolves aspects of the acid-carboxylate controversy by demonstrating the acid nature of the end-groups.
- The findings contribute to understanding modulated phases and phase transitions in similar systems.
Related Concept Videos
01:29Indirect-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
Indirect-acting cholinergic agonists are agents that interact with the acetylcholinesterase enzyme in the synaptic cleft, preventing the breakdown of acetylcholine into choline and acetate. Consequently, the concentration of acetylcholine in the synaptic cleft increases. These agonists can be classified into reversible and irreversible inhibitors based on their duration of action.
Reversible inhibitors display short to medium durations of action. Short-acting agents include simple alcohols with...
Reversible inhibitors display short to medium durations of action. Short-acting agents include simple alcohols with...
01:18Indirect-Acting Cholinergic Agonists: Mechanism of Action
Indirect-acting cholinergic agonists work by interacting with an enzyme called acetylcholinesterase (AChE) in the synaptic cleft. They can be reversible or irreversible inhibitors and have different effects on the enzyme.
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...
01:17Nondepolarizing (Competitive) Neuromuscular Blockers: Mechanism of Action
Nondepolarizing neuromuscular blockers induce paralysis by competitively blocking nicotinic acetylcholine receptors at the muscle end plate. Examples include pancuronium, mivacurium, vecuronium, and rocuronium. These quaternary ammonium derivatives are administered intravenously, are poorly absorbed, and are excreted via the kidneys.
Competitive antagonists prevent acetylcholine from binding to its receptor, inhibiting membrane depolarization. Without conformational changes or intrinsic...
Competitive antagonists prevent acetylcholine from binding to its receptor, inhibiting membrane depolarization. Without conformational changes or intrinsic...
01:11Nondepolarizing (Competitive) Neuromuscular Blockers: Pharmacokinetics
All neuromuscular blocking agents are injected intravenously because they are poorly absorbed from the GI tract. Rapid onset is achieved with intravenous administration, although absorption is also adequate from an intramuscular injection. Since these agents are highly ionized, they do not readily penetrate cell membranes or cross the blood-brain barrier.
Instead, they are transported by the blood to different tissues. Muscles with a greater blood supply (arteries) and blood flow receive more...
Instead, they are transported by the blood to different tissues. Muscles with a greater blood supply (arteries) and blood flow receive more...
01:19Depolarizing Blockers: Pharmocokinetics
Depolarizing blockers are administered through intravenous injection. Succinylcholine is the most common choice of depolarizing blockers in emergency clinical practices. Although they have a rapid onset, they readily diffuse away from the motor end plate into the extracellular fluid. They are metabolized by enzymes such as liver butyrylcholinesterase and plasma pseudocholinesterases. This produces a short duration of action, typically 5-10 minutes long, unlike nondepolarizing blockers, which...
01:19Phase II Reactions: Sulfation and Conjugation with α-Amino Acids
Sulfation and α-amino acid conjugation are two critical biotransformation reactions in drug metabolism. Sulfation, a phase II biotransformation reaction, involves adding a polar sulfate group to a drug, enhancing its water solubility and promoting excretion. This process can either co-occur with or occur independently of glucuronidation. Nonmicrosomal sulfotransferase enzymes catalyze the process. The reaction involves 3'-phosphoadenosine-5'-phosphosulfate or PAPS coenzyme activation, sulfur...