Photo-reactive Clickable trans-Sterol Probe

This is a 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 attachment 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.