Search for Millimeter Microwave Effects on Enzyme or Protein Functions

Recent observations of nonthermal, resonant biological responses to weak millimeter microwave irradiation have led us to investigate whether similar influences exist on enzymatic functions in vitro. We chose (i) the reduction of ethanol in the presence of alcohol dehydrogenase and (ii) the cooperative binding of oxygen on hemoglobin. Using an irradiation intensity near 10 mW/cm the frequency was continuously varied from 40 to 115 GHz with a resolution of a few MHz. No micro­ wave influences were detectable within our experimental sensitivity of about 0.1% of the reaction rate in (i), or of the amount of bound oxygen at half saturation in (ii).