Oxygen and Carbon Dioxide Transport by 

 Blood Containing Haemocyanin 



H. P. WOLVEKAMP 



A general survey of the properties of the haemocyanins in relation 

 to their biological significance is given. Apart from results pre- 

 viously published by other workers in this field as well as by the 

 author, some new data on the blood of Homarus and Cancer, and 

 on the respiration of Sepia are recorded. 



Haemocyanin, the copper-containing blood pigment dissolved in the 

 blood of the cephalopods, a number of gasteropods, the decapod 

 Crustacea, Limulus and the scorpions, for a time excited the interest 

 of biochemists and physiologists because oxygen dissociation curves 

 of a simple hyperbolic shape had been obtained from experiments on 

 solutions of some types of this blood pigment. For our understanding 

 of the mechanism of oxygenation, however, later studies on haemo- 

 globin, of which the chemical properties are much better known, have 

 been much more illuminating. Now, though from a general biochemical 

 point of view the study of haemocyanin perhaps has lost some of its 

 attraction, it still presents a number of characteristics and offers some 

 problems that will excite the interest of workers in the field of com- 

 parative biochemistry and physiology. 



As my personal relation with physical chemistry proper rather 

 resembles that of Moses with Canaan when he, standing on the mount 

 of Nebo, was permitted to see the land of promise from afar but not 

 allowed to go thither, I shall in the following confine myself mainly 

 to the biological aspects of blood gas transport. Accordingly I shall 

 only very briefly summarize some biochemical data. 



The structure of the prosthetic group that can be split off by alkali 

 is largely unknown. The copper it contains combines reversibly with 

 oxygen in a ratio of two atoms of copper to one molecule of oxygen as 

 has been ascertained by Begemann 1 (1924), Redfield and his co-workers 

 (1928) and by Guillemet and Gosselin 1 (1932). 



Millikan 1 (1933) found that oxygenation and reduction proceed 

 with a velocity comparable to oxygenation and reduction of haemo- 

 globin. 



A true oxidation product, methaemocyanin can be formed, but this 

 compound retains the power to combine reversibly with oxygen. 

 Accordingly in gasometric determinations of the quantity of oxygen 



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