Neocarzinostatin

Neocarzinostatin is a macromolecular chromoprotein antibiotic with anti-tumoral activity secreted by Streptomyces macromomyceticus.

It consists of a labile chromophore (bicyclic dienediyne structure, Mr = 659) that is tightly and non-covalently bound to an apoprotein (113 amino acids) with high affinity (Kd ~ 10-10M). The chromophore is a very potent DNA-damaging agent; it is very labile and the role of the apoprotein is to protect it and release it to the target DNA. Other members of the Neocarzinostatin group of antibiotics are macromomycin, actinoxanthin, kedarcidin and maduropeptin.