PLANT AGGLUTININS (LECTINS) II 79 



The assignment of the aldohexoses and aldopentoses to Makela's 

 four groups and the steric similarities of these sugars in each classi- 

 fication are shown in Fig. 6-5. The relation between the pentoses and 

 hexoses shown in books on organic chemistry is based on possible 

 synthetic pathways in the laboratory and does not always show the 

 actual spatial relations of the ring structures. 



Kriipe observed that the agglutinin of Ricinus communis was in- 

 hibited by sugars which fall into Makela's group 2, and the agglutinin 

 of Pisum sativum by sugars of group 3. Apparently these two "non- 

 specific" agglutinins do show a certain degree of specificity. In his 



2 



-0. 



H0X3 



OH 



HO 



*o 



3 



•0. 



Fig. 6-4. Clas.sification of pyranosc forms of sugars into four groups on the 

 basis of the configuration of carbons 3 and 4 (Makelii, 1957). 



more extensive study Makela found many other leguminous seeds 

 having agglutinins which fell into one of these two classes. Other 

 legumes did not fall into either class. In addition to seeds with ag- 

 glutinins inhibited by sugars of groups 2 and 3, Makela's tables give 

 examples of seeds not inhibited by any sugars tested but inhibited 

 by blood group substances and some seeds that are not inhibited by 

 any of the substances tried. 



Among plants the seeds of which contain agglutinins inhibited 

 by sugars of group 2 are Bandeiraca simplicifolia, various species of 

 Bauhinia, Sophora japonica, various species of Crotalaria, various 

 species of Cytisus, various species of Caragana, Wisteria cJiinensis , 

 Coronilla varia, various species of Erythrina, and Glycine soja. In- 

 hibited by sugars of group 3 are Parkia filicoidea, Lathyrus latifolitis. 



