Work

Selective Excitation of the 1Lα State of Tryptophan in Collagen-like Peptides Can Reveal the Formation of a Heterotrimer

Year: 2024

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Fluorescence emission from tryptophan residues has been often used to probe the protein structure due to its transition dipole moment sensitivity to the local environment. We report the fluorescence study of a collagen-like peptide heterotrimer modified with the tryptophan in the X position (X-Y-Gly) n that shows the diminished fluorescence in a homotrimer versus a heterotrimer when the 1 L α state is selectively excited. This behavior is only observed in folded peptides, below the helix-to-coil transition temperature, and can be explained by long-range interactions between the tryptophans located on different strands within the triple helix, not by the change in the local environment. Our results suggest that tryptophan homotransfer is possible at distances much longer than the R 0 (0.5–0.7 nm) previously estimated. These observations imply that the energy transfer between the 1 L α states of proximal tryptophans can be facilitated by constraining their rotation by the helix and, thus, can be employed as a reporter of heterotrimer formation in biosensors.

Source: ACS Omega

DOI: 10.1021/acsomega.4c03600

Authors: Miriam Torrez, Aleksandra Brajanovska, Katarzyna Slowinska

Institution: California State University, Long Beach

Language: English

Topic: Photochemistry and Electron Transfer Studies

Subfield: Physical and Theoretical Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,935

Funders: National Institutes of Health, California State University Long Beach, National Institute of General Medical Sciences