our estimates of n ' obtained with the more reliable data of the higher members of salt series are in the ranges of 19 and 27 amino acid groups , shown by the x-ray crystallographic structure of horse and human hemoglobin of perutz ( perutz , m.f. , et al . ( 1968 ) , nature ( london ) 219 , 131 ) and fermi ( ( 1975 ) j. mol . biol . 97 , 237 ) for the smaller alpha1 beta2 contact areas in the tetrameric structure .
C0086418
human
C1417683
beta2