Revealing the reaction path of UVC bond rupture in cyclic disulfides with ultrafast x-ray scattering

Abstract:

Disulfide bonds are ubiquitous molecular motifs that influence the tertiary structure and biological functions of many proteins. Yet, it is well known that the disulfide bond is photolabile when exposed to ultraviolet C (UVC) radiation. The deep-UV–induced S─S bond fragmentation kinetics on very fast timescales are especially pivotal to fully understand the photostability and photodamage repair mechanisms in proteins. In 1,2-dithiane, the smallest saturated cyclic molecule that mimics biologically active species with S─S bonds, we investigate the photochemistry upon 200-nm excitation by femtosecond time-resolved x- ray scattering in the gas phase using an x-ray free electron laser. In the femtosecond time domain, we find a very fast reaction that generates molecular fragments with one and two sulfur atoms. On picosecond and nanosecond timescales, a complex network of reactions unfolds that, ultimately, completes the sulfur dissociation from the parent molecule.

Additional Resources

DOI: 10.1126/sciadv.adp9175

Bibtex:

@article{mal25revealing,
author = {Lingyu Ma  and Wenpeng Du  and Haiwang Yong  and Brian Stankus  and Jennifer M. Ruddock  and Andrés Moreno Carrascosa  and Nathan Goff  and Yu Chang  and Nikola Zotev  and Darren Bellshaw  and Thomas J. Lane  and Mengning Liang  and Sébastien Boutet  and Sergio Carbajo  and Joseph S. Robinson  and Jason E. Koglin  and Michael P. Minitti  and Adam Kirrander  and Theis I. Sølling  and Peter M. Weber },
title = {Revealing the reaction path of UVC bond rupture in cyclic disulfides with ultrafast x-ray scattering},
journal = {Science Advances},
volume = {11},
number = {3},
pages = {eadp9175},
year = {2025},
doi = {10.1126/sciadv.adp9175},
URL = {https://www.science.org/doi/abs/10.1126/sciadv.adp9175},
eprint = {https://www.science.org/doi/pdf/10.1126/sciadv.adp9175},
}