PXD052768-1

PXD052768 is an original dataset announced via ProteomeXchange.

Title	Linear vs Spirocyclic Dialkyldiazirine Probes for Photoaffinity Labeling
Description	Dialkyldiazirines have emerged as a photoaffinity probe of choice for interactome mapping in live cell experiments. Upon irradiation, ‘linear’ dialkyldiazirines produce dialkylcarbenes, which are susceptible to both intramolecular reactions and unimolecular elimination processes, as well as diazoalkanes, which also participate in intermolecular labeling. Cyclobutylidene has a nonclassical bonding structure and is stable enough to be captured in bimolecular reactions. Cyclobutanediazirines have more recently been studied as photoaffinity probes based on cyclobutylidene, but the mechanism, especially with respect to the role of putative diazo intermediates, was not fully understood. Here, we show that photolysis (365 nm) of cyclobutanediazirines can produce cyclobutylidene intermediates as evidenced by formation of their expected bimolecular and unimolecular products, including methylenecyclopropane derivatives. Unlike linear diazirines, cyclobutanediazirine photolysis in the presence of tetramethylethylene produces a [2+1] cycloaddition adduct. By contrast, linear diazirines produce diazo compounds upon low temperature photolysis in THF, whereas diazo compounds are not detected in similar photolyses of cyclobutanediazirines. Diazocyclobutane, prepared by independent synthesis, is labile, reactive toward water, and capable of protein alkylation. The rate of diazocyclobutane decomposition is not affected by 365 nm light, suggesting that the photochemical conversion of diazocyclobutane to cyclobutylidene is not an important pathway. Finally, chemical proteomic studies revealed that a likely consequence of this primary conversion to a highly reactive carbene is a marked decrease in labeling by cyclobutanediazirine-based probes relative to linear diazirine counterparts both at the individual protein and proteome-wide levels. Collectively, these observations are consistent with a mechanistic picture for cyclobutanediazirine photolysis that involves carbene chemistry with minimal formation of diazo intermediates, and contrasts with the photolyses of linear diazirines where alkylation by diazo intermediates plays a more significant role.
HostingRepository	PRIDE
AnnounceDate	2024-10-15
AnnouncementXML	Submission_2024-10-15_01:50:09.385.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Louis Conway
SpeciesList	scientific name: Homo sapiens (Human); NCBI TaxID: 9606;
ModificationList	TMT6plex-126 reporter+balance reagent acylated residue; iodoacetamide derivatized residue
Instrument	Orbitrap Fusion Lumos

Revision	Datetime	Status	ChangeLog Entry
0	2024-05-31 17:56:57	ID requested
⏵ 1	2024-10-15 01:50:10	announced
2	2024-10-22 07:01:33	announced	2024-10-22: Updated project metadata.

10.1039/D4SC04238G;

submitter keyword: Photoaffinity

Christopher G Parker
contact affiliation	Department of Chemistry, Scripps Research
contact email	cparker@scripps.edu
lab head
Louis Conway
contact affiliation	Scripps Research
contact email	lconway@scripps.edu
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD052768
     1. Label: PRIDE project
     2. Name: Linear vs Spirocyclic Dialkyldiazirine Probes for Photoaffinity Labeling