The kinetics of DNAse inhibition by specific antibodies

The inhibition of beef pancreatic deoxyribonuclease I activity with specific antibodies is studied using the hypochromic shift of DNA at 260 nm. The kinetics of this reaction reveals two reaction phases. The first phase, which ends within seconds, is reversible and follows second order kinetics. It leads quickly to the formation of big complexes. The second phase, which reaches completion within minutes before precipitation is detectable, is essentially irreversible and follows zero order kinetics. A model explaining these results is suggested.