PLANT AGGLUTININS (LECTINS) II 83 



transport, and perhaps immobilize in the seed one or more of the 

 carbohydrates with which they have the power to combine. Kriipe 

 (1956) first suggested the possible role of the lectins as "Kohlen- 

 hydratfixierer" ("carbohydrate catchers"), and Boyd, Everhart, and 

 McMaster (1958) also thought that lectins might so function in the 

 plant. 



Lessons from the Stutly of Lectins 



The study of plant agglutinins promises to throw new light on the 

 specificity of the blood group antigens and on the nature and number 

 of carbohydrate groupings which are present on the surface of the 

 erythrocyte. I shall discuss this in the following chapter. Study of 

 inhibition reactions of the lectins has already thrown considerable 

 light on the structure of the ABH antigens. The difference in specifi- 

 city between lectins and human and animal agglutinins, whether we 

 care to regard this difference as evidence that lectins are less specific 

 or more specific, makes lectins particularly suitable for a study by 

 the inhibition reaction of the cell receptors. (See Chapter 7.) 



The greater homogeneity of the lectins with regard to specificity 

 presents an interesting contrast with antibodies and might suggest 

 that a protein molecule which has a certain specificity as a part of its 

 role in metabolism is likely to be more uniform in this respect than a 

 gamma globulin mixture which has acquired a certain specificity by 

 some process of natural selection. This line of thinking may support 

 the antibody-formation theory of Jerne and subsequent modifications 

 thereof. 



References 



Bird, G. W. G., 1959, Brit. Med. Bull. 15, 165. 



Boyd, W. C., 1960, /. Immunol. 84, 231. 



Boyd, W. C, D. L.Everhart, and M. H. McMaster, 1958, /. Immunol. 81, 414. 



Boyd, W. C, and E. Shapleigh, 1954a, Science 119, 419. 



Boyd, W. C., E. Shapleigh, and M. H. McMaster, 1955, Arch. Biochcm. Biophys. 



55, 226. 

 Boyd, W. C., and E. Shapleigh, 1954d, /. Immunol. 73, 226. 



r^)Oyd, W. C, and E. Waszczenko-Zacharczenko, 1961, Transfusion, 1, 223. 



ICnsgraber, A., M. Krupe, and R. Ensgraber-Hattingen, 1960, Z. Immunitats- 

 forsch. 120, 340. 



