C-type animal lectins

Fig. 2. Summary of structural features of C-type animal lectins. The (nearly) invariant residues found in the coimnon carbohydrate-recognition domain of the C-type lectins are shown, flanked by schematic diagrams of the special effector domains (if any) found in individual members of the family. GAG, glycosaminoglycan EGF, epidermal growth factor. Reproduced from K. Drickamer, Two Distinct Classes of Car bohydrate-recognition Domains in Animal Lectins, J. Biol. Chem., 263 (1988) 9557-9560 (Ref. 35) 1988. The American SocietyforBiochemistry Molecular Biology with permission by Professor Kurt Drickamer and The American Society for Biochemistry Molecular Biology.

The C-type animal lectins include endocytic receptors such as hepatic lectins, macrophage receptors and selectins that mediate the adhesion of leukocytes to... 

Bezouska, K., Vlahas, G., Horvath, O., Jinochova, G., Fiserova, A., Giorda, R., Chambers, W.H., Feizi, T. and Pospisil, M. (1994a) Rat natural killer cell antigen, NKR-Pl, related to C-type animal lectins is a carbohydrate-binding protein. J. Biol. Chem., 269,16945-16952. 

R 471 J. Pavlicek, D. Kavan, P. Pompach, P. Novak, O. Luksan and K. Bezouska, Lymphocyte Activation Receptors New Structural Paradigms in Group V of C-Type Animal Lectins , Biochem. Soc. Trans., 2004,32,1124... 

Chambers WH, Adamkiewicz T, Houchins JP (1993) Type II integral membrane proteins with characteristics of C-type animal lectins expressed by natural killer (NK) cells. Glycobiology 3 9-14... 

Figure 4. Summary of the structures of several groups of C-type animal lectins. Figure 1 in reference 16 is modified.

Hemagglutinins may be of several types (a) nonspecific lectins that agglutinate cells without regard to their origin (either species, or blood type), (b) lectins that preferentially agglutinate the cells of one or several kinds of animals, or (c) blood-group-specific lectins. 

Figure 11.29. Structure of a C-Type Carbohydrate-Bindiug Domain from an Animal Lectin. A calcium ion links a mannose residue to the lectin. Selected interactions are shown, with some hydrogen atoms omitted for clarity.

Lectins can be divided into classes on the basis of their amino acid sequences and biochemical properties. One large class is the C type (for calcium-requiring) found in animals. These proteins each have a homologous domain of 120 amino acids that is responsible for carbohydrate binding. The structure of one such domain bound to a carbohydrate target is shown in Figure 11.26. 

Structure of a C-type carbohydrale-binding domain from an animal lectin Figure 11.26... 

---