the distance and driving-force dependences of electron transfer ( et ) in a set of four surface-ruthenated myoglobins , in which the heme prosthetic group has been systematically replaced by a series of metalloporphyrins of differing excited-state redox potentials , have provided information on the magnitude [ hab ( 12.7 a ) approximately 6.3 x 10 ( -3 ) cm-1 ] and decay [ beta approximately 0.8 a-1 , where ket alpha exp [ -beta ( d - do ) ] ] of protein-mediated donor-acceptor electronic coupling .
C0018966
heme
C0025541
metalloporphyrins