that the modification of only one j 3 chain is not enough to block the interaction of the molecule as a whole with oxygen. Since this derivative also exhibits the myoglobin type of oxygen-binding curve, the interchain crosslinking, i. e. the fixation of the quaternary structure of the protein according to the model, can hinder the rearrangement from the deoxy form into the oxy form as effectively as the blockage of the terminal histidines of the p chains. The change in the quaternary structure, according to these experiments, is then a necessary condition for the transition between the oxy and deoxy forms of the tertiary structures.

No abstract

Die Umsetzungen nach G1. (1) und GI. (2) werden bei 80°C durch Radikale aus Azoisobuttersaure-nitril oder schon bei 28 "C durch UV-Belichtung (h,,, = 254 nm) stark beschleunigt oder iiberhaupt ermoglicht.