Photo-reactive Clickable cis-Sterol Probe

Photo-activatable sterol probe for the bioorthogonal tagging and enrichment of sterol-binding biomolecules. This sterol probe contains an intact steroid core structure bearing a diazirine UV-activatable cross-linking group, as well as an alkyne group for click-chemistry mediated adduction of reporter and affinity tags. The probes are cell-permeable, allowing for in situ labeling of biomolecules in live cells, as well as in cell extracts in vitro.

Handle the probes in amber vessels under dim ambient light whenever possible. Aqueous solutions of probes complexed to methyl-β-cyclodextrin (20:1 = m-β-CD:probe molar ratio, 5-20 μM probe) permeate cultured cells in complete serum-containing medium within 30 minutes at 37°C and are cross-linked using near-UV (365 nm) light for 3-10 minutes. Cells can then be harvested and lysed, fractionated or otherwise processed. Click chemistry (Cu(I)-catalyzed 1,3-dipolar cycloaddition of the alkyne with an azide reporter tag such as a fluorophore or biotin, products 760765 or 762024) can be performed in protein samples in PBS for gel-visualization of probe-labeling, MS-based proteomics analysis of probe-mediated affinity enrichments or western blot analysis.