Enzyme degradation: mechanism of auger-destruction

Oksengendler B.L., Strokovich K.E., Ruban I.N., Voropaeva N.L.

Institute of Chemistry and Physics of Polymers of Academy of Sciences of Uzbekistan

Multi-electron atoms are known to be the co-factor of the great number of enzymes. This fact opens specific channels for the effect of low energy ionizing radiation. For example, a biopolymer containing multielectron atom of metal as enzyme co-factor, is exposed to X-rays, -particles, or ions flux. We consider the ionization of deep shells of this metallic atom resulting in atom transformation into multicharged ion Z by Auger-cascade. To decompose the biomolecule by electrostatic forces, electrostatic energy of Auger charge must exceed the material strength (). So, the crossection of enzyme radiational decomposition through Auger-destruction channel can be expressed as:

where - ionization crossection of deep chell of co-factor atom; - specific time of ion decomposition; - specific life time of cloud of holes at one lattice point after metal atom ionization; - the spectrum of Auger charges yield.

In the case of narrow yield distribution of Auger charges , the yield of one enzyme decomposition resulting from one ionization of deep chell can be expressed as:


where - correlation factor for Auger holes; - probability of Auger cascade.

Estimation gives the value of , that is rather sufficient value for radiational inactivation of bioobjects (see H. Jung, 1967).