Related Experiment Video
Updated: Aug 10, 2026

Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Effect of stacking interactions with poly(riboadenylic acid) on the triplet state properties of tryptophan
Abstract:
Optically detected magnetic resonance (ODMR) signals of tryptophan (Trp) have been measured in L-lysyl-L-tryptophyl-L-lysine (Lys-Trp-Lys) and in its complex with poly(riboadenylic acid) [poly(rA)]. Measurements were made with optical narrow band detection through the Trp O-O band. Plots of [D] and [E] vs. lambda are distinctly different for Lys-Trp-Lys and its complex with poly(rA). A reduction of [D], in particular, is consistent with stacking of Trp with adenine in the complex, since this effect is expected from charge-transfer contributions in the excited triplet state. Triplet energy transfer from poly(rA) to Lys-Trp-Lys is nearly complete at 77 K, with a Trp:adenine ratio of 0.1. The energy transfer efficiency is considerably reduced at 4.2 K and below, probably resulting from reduction of the triplet mobility in the polymer. Analysis of the phosphorescence decays shows that the triplet states of poly(rA), Lys-Trp-Lys, and their complex decay nonexponentially. Binding of polylysine to poly(rA) has no effect on the phosphorescence spectrum, but the decay kinetics are changed.
More Related Videos
09:31PCR Mutagenesis, Cloning, Expression, Fast Protein Purification Protocols and Crystallization of the Wild Type and Mutant Forms of Tryptophan Synthase
Published on: September 26, 2020
12:07Chemical Modification of the Tryptophan Residue in a Recombinant Ca2+-ATPase N-domain for Studying Tryptophan-ANS FRET
Published on: October 9, 2021
Related Concept Videos
Ligand Binding and Linkage
Cooperative Allosteric Transitions
Transcription Attenuation in Prokaryotes
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
Repressible Operon: trp Operon