2.B.6 The Ionomycin (Ionomycin) Family

Ionomycin is an ionophoric antibiotic synthesized by Streptomyces conglobatus sp. Treja. It functions as an antibiotic against many Gram-positive bacteria. The 1:1 Ca2+ complex has the formula C41H70O9Ca2+ (MW = 747). It is a lipid soluble divalent cation-specific ionophore that transports divalent cations across biological and artificial membranes by a carrier-type mechanism. It exhibits cation selectivity in the order: Pb2+ > Cd2+ > Zn2+ > Mn2+ > Ca2+ > Cu2+ > Co2+ > Ni2+ > Sr2+.

The generalized reaction catalyzed by ionomycin is:

C2+(out)C2+(in). (C2+ = divalent cation)



Bennett, J.P., S. Cockcroft and B.D.Gomperts. Ionomycin stimulates mast cell histamine secretion by forming a lipid-soluble calcium complex. Nature 282: 851-853.

Erdahl, W.L., C.J. Chapman, R.W. Taylor, and D.R. Pfeiffer. (2000). Ionomycin, a carboxylic acid ionophore, transports Pb(2+) with high selectivity. J. Biol. Chem. 275: 7071-7079.

Liu, W.C., D.S. Slusarchyk, G. Astle, W.H. Trejo, N.E. Brown and E. Meyers (1978). Ionomycin, a new polyether antibiotic. J. Antibiot. 9: 815-819.


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