Structure, Bonding, and Photoaffinity Labeling Applications of Dialkyldiazirines

Abstract

Dialkyldiazirine photoaffinity probes are unparalleled tools for the study of small molecule-protein interactions. Here we summarize the basic principles of structure, bonding, and photoreactivity of dialkyldiazirines, current methods for their synthesis, and their practical application in photoaffinity labeling experiments. We demonstrate the unique utility of dialkyldiazirine probes in the context of our recent photoaffinity crosslinking-mass spectrometry analysis to reveal a hidden cholesterol binding site in the Hedgehog morphogen proteins.

A bifunctional imidazolium-based cholesterol analog for the tracking of cellular cholesterol distributions and cholesterol–protein interactions

“…Diazirines are widely used for photo-crosslinking in biological environments as they release N 2 upon UV light irradiation, thus yielding a highly reactive carbene that readily inserts into nearby C–H bonds thereby establishing a covalent crosslink. 12 The functional moieties of the bifunctional linker section, which is derived from a naturally abundant amino acid scaffold ( l -phenylalanine), are attached via amide bonding to ensure sufficient stability in biological environments. The rigid phenyl connection between linker section and imidazolium–cholesterol scaffold conserves positioning and directionality of the linker outside of the membrane, thus (a) decreasing undesired interaction and thereby a potential perturbance of correct membrane integration by the linker section and (b) exposing the crosslinker at the membrane surface.…”

A Combination of Computational and Experimental Studies to Correlate Electronic Structure and Reactivity of Donor–Acceptor Singlet Carbenes

“…Carbene chemistry has laid to the foundation of numerous attractive areas of research with respect to organic transformation. [1][2][3][4][5][6][7][8][9][10][11][12][13] Metal carbenoids generated from donor-acceptor (D-A) diazo compounds (like aryl diazoacetates) have been investigated extensively. [14][15][16][17][18][19][20][21][22][23] Aryl ring adjacent to carbene contributes as a donor moiety and the ester part imposes an electron-withdrawing effect to the carbene carbon thus constructing the acceptor moiety.…”