Spiro[3H-diazirine-3,6'-cholan]-24'-oic acid, 3'-hydroxy-, 5-hexyn-1-yl ester, (3'β,5'α)-

PhotoClick Cholesterol is a clickable, photo-reactive sterol probe used in combination with quantitative mass spectrometry to globally map cholesterol-protein interactions directly in living cells. In addition to the UV-activatable cross-linking diazirine group that reacts with proteins, the sterol contains an alkyne group for incorporation of reporter and affinity tags through click-chemistry.

PhotoClick Cholesterol serves as a probe for tracking cholesterol-binding proteins. The copper-catalyzed azide-alkyne cycloaddition is the basis for its probe functionality. The alkyne group is essential for the click chemistry property. Its binding to partners is mediated by photocrosslinking.

[1] N. CHAUHAN. A PhotoClick cholesterol‐based quantitative proteomics screen for cytoplasmic sterol‐binding proteins in Saccharomyces cerevisiae[J]. Yeast, 2019, 37 1: 15-25. DOI: 10.1002/yea.3448