Amide Hydrogen Deshielding
Amide Hydrogen Deshielding - Related Videos
07:15
Amide Hydrogen/Deuterium Exchange & MALDI-TOF Mass Spectrometry Analysis of Pak2 Activation
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Cited by 2 •
2011
MALDI-TOF mass spectrometry was successfully utilized to monitor the amide hydrogen/deuterium exchange in protein kinase Pak2 activation.
06:06
Hydrogenation
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2023
Source: Vy M. Dong and Zhiwei Chen, Department of Chemistry, University of California, Irvine, CA This experiment will demonstrate the hydrogenation of chalcone as an example of an alkene hydrogenation reaction (Figure 1). In this experiment, palladium on carbon (Pd/C) will be used as a heterogeneous catalyst for the process. A balloon will be used to supply the hydrogen atmosphere. Figure 1: Diagram showing the hydrogenation of chalcone to 3-phenylpropiophenone.
01:29
Preparation of Amides
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2023
Amides are synthesized by treating carboxylic acids with amines in the presence of dehydrating agents like dicyclohexylcarbodiimide (DCC). The DCC-promoted synthesis of amides begins with the protonation of DCC by carboxylic acid. The protonation makes it a better acceptor. Next, the addition of carboxylate to the protonated carbodiimide gives a reactive acylating agent. Subsequently, the amine acts as a nucleophile that attacks the acylating agent to form a tetrahedral intermediate. In the...
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...
01:19
Amines to Amides: Acylation of Amines
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2025
Various carboxylic acid derivatives (such as acid chlorides, esters, and anhydrides) can be used for the acylation of amines to yield amides. The reaction requires two equivalents of amines. The first amine molecule functions as a nucleophile and attacks the carbonyl carbon to produce a tetrahedral intermediate. This is followed by the loss of the leaving group and restoration of the C=O bond. Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary amide...
FAQs
An amide proton’s chemical shift reflects several local influences rather than the carbonyl group alone. The electron-withdrawing carbonyl reduces shielding, while hydrogen bonding and backbone conformation further alter the proton’s magnetic environment. Considering these effects together helps explain why chemically similar amide sites can show different resonances within the same protein or peptide.
Hydrogen bonding matters because it changes the electronic environment around an amide proton, while solvent exposure affects how strongly that site interacts with its surroundings. Exchange with water adds another source of variability. These factors can change observed shifts independently or together, so interpretation requires attention to the local structural and solution context.
Backbone conformation links amide hydrogen deshielding to secondary structure. When the protein backbone adopts different structural arrangements, the resulting local environments can produce different amide chemical shifts. Mapping those shifts across a sequence therefore provides a way to assess secondary-structure formation, rather than treating each resonance as an isolated property of a single proton.
Analysis begins with measuring amide-related chemical shifts and relating their changes to the structural context of the protein or peptide. Researchers can then evaluate whether the pattern is consistent with hydrogen bonding, secondary-structure formation, solvent exposure, or conformational change. The outcome is an indirect structural readout based on local magnetic environments rather than a direct visual observation.
During protein-folding studies, shifts in amide hydrogen environments can reveal changes in local structural organization. Because the signals respond to backbone conformation and hydrogen bonding, they help track secondary-structure formation in the folding system. This makes the measurements useful for connecting folding behavior with specific residue environments in proteins and peptides.
Changes associated with ligand binding can be examined through amide chemical shifts because binding alters the environments of affected residues. The resulting signal changes help identify residues whose local surroundings respond to the interaction and can support characterization of molecular interactions in solution. This approach is therefore relevant to studying protein-ligand interactions and related solution-phase systems.