The Reaction between Oxygen and Hemoglobin. 79 



1. When the globin is split off from the hemoglobin molecule 

 the iron-component can be identified as hematin (or its reduction 

 product, hemochromogen), which has a characteristic spectrum. 

 All of our spectroscopic and spectrophotometric evidence is against 

 the presence of hematin or hemochromogen in normal blood or in 

 solutions of freshly prepared oxyhemoglobin. I have recently 

 been able to split hemoglobin in glycerin solution by means of 

 (NH 2 )2-H 2 0 reversibly into globin + hemochromogen. The re- 

 action, however, only takes place under special conditions and is 

 always accompanied by sharp spectral changes. 



2. Granted for the moment that hemoglobin is hydrolyzed in 

 aqueous solution. Then it must be possible to shift the equilib- 

 rium by changing the concentration of H' or OH' ions. Following 

 experiments 1 show that such a shift of equilibrium does not 

 occur or at least if it does it has no influence on the combination 

 of oxygen with hemoglobin at constant pressure. Similar results 

 were obtained with KOH. On increasing the H' or OH' concen- 

 tration beyond the quantities given in the table a constitutive 

 change occurs in the oxyhemoglobin molecule; methemoglobin is 

 formed. 



Table II. 





c 



Oj-Capacity. 



o, 



Hb 



Quantity of k/io HC1 Added 

 to 4.5 c.c. Washed Rabbit 

 Corpuscles in c.c. 



I 



4.27 



5-97 



1.40 



0.0 



II 



4-47 



6.25 



1.40 



0.5 



III 



4.48 



6-37 



1.42 



1.0 



IV 



4.40 



6-35 



1.44 



2.0 



3. From Bohr's experiments and formula the quantity of O2 

 absorbed pro gram hemoglobin is a function of the total hemo- 

 globin concentration. According to the experiments here pre- 

 sented the quantity of O2 bound pro gram hemoglobin is inde- 

 pendent of the total hemoglobin concentration at constant gas 

 pressure. 



The arguments 2 and 3 against the Bohr formula also hold for 

 Manchot's work. In addition it is to be noted that in our experi- 

 ments the limit value for the oxygen (or CO) absorption is 1 mol. 

 oxygen to 1 mol. hemoglobin. In no case does it approach 2 mol. 



From the pneumococcus study by Dr. Peabody and myself. 



