Ionophores..

These are the substances involved in the passive mediated transport ( or facilitated diffusion) of ions across membranes. They vastly increase the permeability of membranes to particular ions. They transport ions along the concentration gradients.

Ionophores are Organic molecules of diverse types, many of which are antibodies of bacteria origin. Cells and organelle actively maintain concentration gradients of various ions across their membranes (e.g., Na+, K+ - pump). The antibiotic properties of ionophores arise from their tendency to discharge these concentration gradient.

Ceruloplasmin.

About 90% of copper circulating in the blood of normal mammals present as an intensely blue colored protein called Ceruloplasmin. This protein is responsible for the storage and transport of copper. It is synthesized in liver. In addition to blood, it is also found in spinal fluid, joint fluid and gastrointestinal secretion.

Ceruloplasmin is a glycoprotein. The copper atoms are an integral point of Ceruloplasmin structure. There are 7-8 copper atoms per molecule. One half of the copper in crystalline Ceruloplasmin is in Cu2+ state. All these Cu2+ ions are not equivalent. The other half of copper remain in the Cu+ state.

The Cu2+ ions of Ceruloplasmin are reduced by Fe2+ and oxidised by molecular O2 in a cyclic process, called Ferroxidase activity. Ceruloplasmin oxidise (+ve state of ) Fe2+ to Fe3+, which then bind to transferrin.

Patent's suffering from wilson's disease may exhibit masked deficiency of Ceruloplasmin. This copper deficiency inhibits haemoglobin bio synthesis and ultimately leads to death.