Arsenic trioxide targets Hsp60, triggering degradation of p53 and survivin.

The mechanisms of action of arsenic trioxide (ATO), a clinically used drug for the treatment of acute promyelocytic leukemia (APL), have been actively studied mainly through characterization of individual putative protein targets. There appear to be no studies at a system level. Herein, we integrate metalloproteomics through a newly developed organoarsenic probe, As-AC (CHAsNOS) with quantitative proteomics, allowing 37 arsenic binding and 250 arsenic regulated proteins to be identified in NB4, a human APL cell line.

Plasmonic metal nanoparticles as efficient mass tags for ion signal amplification and ultrasensitive detection of protein markers.

The development of sensitive and specific analytical methods is critical for the discovery of molecular biomarkers, which assists disease diagnosis and understanding biological processes. Herein, a highly sensitive method is developed using antibody-conjugated plasmonic metal nanoparticles for the detection of targeted biomarkers down to low attomole level via coupling of immunoassay techniques with laser ionization mass spectrometry (LI-MS). The conjugated antibodies target specific antigens, while the metal nanoparticles act as mass tags and ion reservoirs for the signal amplification.