Histone-produced magnesium extrusion from mitochondria and magnesium binding to histone.

Histone (60 microgram/mg mit. protein) extrudes Mg2+ from mitochondria by 30% with the utilization of endogenous substrates; in the presence of rotenone extrusion drops to about 18%. Dinitrophenol and ADP prevent this effect of histone. Mg2+ extrusion produced by histone depends on histone concentration being at a maximum (100% extrusion) at 107 microgram histone/mit. protein. It was found also that histone alone binds Mg2+ (1.6 nmol Mg2+/microgram histone).