SELECTIVE-INHIBITION OF THE MITOCHONDRIAL PERMEABILITY TRANSITION PORE AT THE OXIDATION-REDUCTION SENSITIVE DITHIOL BY MONOBROMOBIMANE

In this paper we introduce monobromobimane, a thiol reagent, as a sele ctive blocker of the recently identified dithiol whose oxidation-reduc tion status modifies voltage sensing by the mitochondrial permeability transition pore, a cyclosporin A-sensitive channel. Monobromobimane d oes not inhibit the phosphate carrier, nor does it interfere with Ca2 transport, energy coupling or ATP production and transport, We show t hat monobromobimane selectively prevents the shift in pore gating pote ntial caused by some dithiol oxidants or crosslinkers but not by incre asing [Ca2+], allowing a clear distinction of the pore agonists which act at this site.