Development of a Novel Sulfoxide-Containing MS-Cleavable Homobifunctional Cysteine-Reactive Cross-Linker for Studying Protein-Protein Interactions.

Cross-linking mass spectrometry (XL-MS) has become an emerging technology for defining protein-protein interactions (PPIs) and elucidating architectures of large protein complexes. Up to now, the most widely used cross-linking reagents target lysines. Although such reagents have been successfully applied to map PPIs at the proteome-wide scale, comprehensive PPI profiling would require additional cross-linking chemistries.

UV photodissociation dynamics of CHICl and its role as a photolytic precursor for a chlorinated Criegee intermediate.

Photolysis of geminal diiodoalkanes in the presence of molecular oxygen has become an established route to the laboratory production of several Criegee intermediates, and such compounds also have marine sources. Here, we explore the role that the trihaloalkane, chlorodiiodomethane (CHICl), may play as a photolytic precursor for the chlorinated Criegee intermediate ClCHOO. CHICl has been synthesized and its UV absorption spectrum measured; relative to that of CHI the spectrum is shifted to longer wavelength and the photolysis lifetime is calculated to be less than two minutes.

The proteasome-interacting Ecm29 protein disassembles the 26S proteasome in response to oxidative stress.

Oxidative stress has been implicated in multiple human neurological and other disorders. Proteasomes are multi-subunit proteases critical for the removal of oxidatively damaged proteins. To understand stress-associated human pathologies, it is important to uncover the molecular events underlying the regulation of proteasomes upon oxidative stress.