Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations01:08

IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations

2.3K
Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single...
2.3K
Peptide Bonds02:43

Peptide Bonds

86.5K
A peptide bond covalently attaches amino acids through a dehydration reaction. One amino acid's carboxyl group and another amino acid's amino group combine, releasing a water molecule. The resulting bond is the peptide bond. The products that such linkages form are peptides. As more amino acids join this growing chain, the resulting chain is a polypeptide. Each polypeptide has a free amino group at one end. This end has the N-terminal, or the amino-terminal, and the other end has a free...
86.5K
Peptide Identification Using Tandem Mass Spectrometry01:33

Peptide Identification Using Tandem Mass Spectrometry

8.8K
Tandem mass spectrometry, also known as MS/MS or MS2, is an analytical technique that employs two mass analyzers. Essentially it is a series of mass spectrometers that helps isolate a particular biomolecule and then helps study its chemical properties.
This technique helps gather information regarding the protein from which the peptide was obtained and to study the peptides’ amino acid sequence. Identifying peptides from a complex mixture is an important component of the growing field of...
8.8K
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)01:20

¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)

1.8K
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
1.8K
IR Spectroscopy: Molecular Vibration Overview01:24

IR Spectroscopy: Molecular Vibration Overview

6.2K
When Infrared (IR) radiation passes through a covalently bonded molecule, the bonds transition from lower to higher vibrational levels. The fundamental vibrational motions that result in infrared absorption can be classified as stretching or bending vibrations.
Stretching vibrations are vibrational motions that occur along the bond line, changing the bond length or distance between two bonded atoms. They are further distinguished as symmetric or asymmetric. In symmetric stretching, the...
6.2K
Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)01:15

Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)

1.2K
Insensitive Nuclei Enhanced by Polarization Transfer (INEPT) is an advanced Nuclear Magnetic Resonance (NMR) technique specifically designed to detect and enhance the signals of low-abundance nuclei, such as carbon-13 and nitrogen-15, in small molecules. The fundamental principle behind INEPT is the transfer of polarization from a more abundant and highly polarizable nucleus, typically hydrogen-1, to the low-abundance nucleus of interest. This process effectively boosts the NMR signal of the...
1.2K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Castanea mollissima shell prevents an over expression of inflammatory response and accelerates the dermal wound healing.

Journal of ethnopharmacology·2018
Same author

Nuclear receptor binding protein 1 correlates with better prognosis and induces caspase-dependent intrinsic apoptosis through the JNK signalling pathway in colorectal cancer.

Cell death & disease·2018
Same author

Development and Applications of Chromosome-Specific Cytogenetic BAC-FISH Probes in <i>S. spontaneum</i>.

Frontiers in plant science·2018
Same author

Neuroprotective effect of berberine agonist against impairment of learning and memory skills in severe traumatic brain injury via Sirt1/p38 MAPK expression.

Molecular medicine reports·2018
Same author

Multidrug-Resistant <i>Escherichia albertii</i>: Co-occurrence of β-Lactamase and MCR-1 Encoding Genes.

Frontiers in microbiology·2018
Same author

Potentials, Challenges, and Genetic and Genomic Resources for Sugarcane Biomass Improvement.

Frontiers in plant science·2018

Related Experiment Video

Updated: Mar 30, 2026

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids
08:53

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids

Published on: March 21, 2025

1.2K

Understanding the Amide-II Vibrations in β-Peptides.

Juan Zhao1, Jianping Wang1

  • 1Beijing National Laboratory for Molecular Sciences; Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, P. R. China.

The Journal of Physical Chemistry. B
|November 4, 2015
PubMed
Summary

This study reveals how amide-II spectral profiles in β-peptides change with helical structure. These findings offer insights into peptide conformation and dynamics using vibrational spectroscopy.

More Related Videos

Stability and Structure of Bat Major Histocompatibility Complex Class I with Heterologous &#946;2-Microglobulin
11:17

Stability and Structure of Bat Major Histocompatibility Complex Class I with Heterologous β2-Microglobulin

Published on: March 10, 2021

6.9K
MALDI Imaging Mass Spectrometry of Neuropeptides in Parkinson's Disease
16:57

MALDI Imaging Mass Spectrometry of Neuropeptides in Parkinson's Disease

Published on: February 14, 2012

27.0K

Related Experiment Videos

Last Updated: Mar 30, 2026

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids
08:53

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids

Published on: March 21, 2025

1.2K
Stability and Structure of Bat Major Histocompatibility Complex Class I with Heterologous &#946;2-Microglobulin
11:17

Stability and Structure of Bat Major Histocompatibility Complex Class I with Heterologous β2-Microglobulin

Published on: March 10, 2021

6.9K
MALDI Imaging Mass Spectrometry of Neuropeptides in Parkinson's Disease
16:57

MALDI Imaging Mass Spectrometry of Neuropeptides in Parkinson's Disease

Published on: February 14, 2012

27.0K

Area of Science:

  • Biophysics
  • Computational Chemistry
  • Spectroscopy

Background:

  • Beta-peptides are valuable biomimetic structures with diverse helical conformations.
  • Amide-II modes are sensitive vibrational probes of peptide backbone structure.
  • Understanding structure-vibration relationships is crucial for interpreting experimental spectra.

Purpose of the Study:

  • To investigate the conformational dependence of amide-II vibrational modes in various β-peptide helices.
  • To analyze the influence of intramolecular hydrogen bonding on amide-II spectral properties.
  • To explore the contributions of through-space and through-bond interactions to vibrational couplings.

Main Methods:

  • Ab initio quantum chemical computations were employed to simulate vibrational spectra.
  • Modeling analysis was used to interpret spectral profiles and coupling mechanisms.
  • Five distinct helical conformations (8-, 10-, 12-, 14-, and 10/12-helices) of β-peptides were examined.

Main Results:

  • Significant conformational dependence of the amide-II spectral profile was observed.
  • Intramolecular hydrogen bonding's influence on transition frequencies and intensities was characterized.
  • Hydrogen bonding was found not to be the primary determinant of vibrational coupling strength.
  • Analysis revealed contributions from both through-space and through-bond interactions to amide-II couplings.

Conclusions:

  • The study provides essential benchmarks for interpreting experimental amide-II infrared spectra of β-peptides.
  • Amide-II vibrational modes show potential for monitoring β-peptide structures and dynamics.
  • Computational insights enhance the understanding of vibrational spectroscopy in biomolecular studies.