Related Experiment Video
Updated: Jul 9, 2026

Quantitative Structure-Activity Relationship, Activity Prediction, and Molecular Dynamics of Non-nucleotide Reverse Transcriptase Inhibitors
Published on: May 9, 2025
Two-dimensional infrared spectra reveal relaxation of the nonnucleoside inhibitor TMC278 complexed with HIV-1 reverse
Chong Fang1, Joseph D Bauman, Kalyan Das
1Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA.
Abstract:
The two nitrile groups at the wings of the nonnucleoside HIV-1 reverse transcriptase (RT) inhibitor TMC278 are both identified in high-sensitivity 2D IR spectroscopy experiments of the HIV-1 RT/TMC278 complex. The vibrational spectra indicate that the two arms of the inhibitor sense quite different environments within the hydrophobic pocket. The vibrational relaxation of the two arms are almost equal at 3 ps from model studies. The 2D IR spectra expose a significant distribution of nitrile frequencies that diffuse at equilibrium on ultrafast time scales ranging from hundreds of femtoseconds to tens of picoseconds. The slow spectral diffusion of the cyanovinyl arm of the inhibitor is attributed to its interaction with the backbone and side chains in the hydrophobic tunnel. The results show that the inhibitor cyano modes lose memory of their structural configurations relative to the hydrophobic pocket within tens of picoseconds. The cross-peaks between the two arms of the drug are tentatively attributed to relaxation of the nitrile state with both arms excited.
More Related Videos
08:33Nucleocapsid Annealing-Mediated Electrophoresis (NAME) Assay Allows the Rapid Identification of HIV-1 Nucleocapsid Inhibitors
Published on: January 19, 2015
13:07Determining 3'-Termini and Sequences of Nascent Single-Stranded Viral DNA Molecules during HIV-1 Reverse Transcription in Infected Cells
Published on: January 30, 2019
Related Concept Videos
IR Spectroscopy: Molecular Vibration Overview
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...
IR Frequency Region: Fingerprint Region
The...
Two-Dimensional (2D) NMR: Overview
The first step is the preparation period, during which nucleus A is excited with a radiofrequency pulse.
IR Spectrum
Transmittance is defined as the ratio of the radiant power passing through a sample to that from the radiation's source. Multiplying the transmittance by 100 gives the percent transmittance (%T), which varies between 100% (no absorption) and 0% (complete...
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
Total Internal Reflection Fluorescence Microscopy