Lentil hemagglutinating activity

Hemagglutinating activity in the common lentil (Lens culinaris or Lens esculenta) was first reported by Landsteiner and Raubitschek.439 Several laboratories have since isolated the lentil lectin in pure form, and studied its physical-chemical properties and interaction with carbohydrates.138,142,143,440 442... 

Metal analysis revealed one atom of Mn2+ and six atoms of Ca2+ associated with each 66.5 kg of protein.142 Addition of 5 mM Ca2+ and mM Mn2+ to the native lectins enhanced both hemagglutination and mannan precipitation. This indicates that either some metal loss occurred during purification, or that the metal binding-sites are never completely occupied442 (compare Refs. 300 and 301). Mn2+ stimulated the hemagglutinating activity of all lentil-lectin preparations more than did Ca2+, whereas Ca2+ promoted mannan precipitation more effectively.442 Demetallization, by dialysis against 0.1 M EDTA followed by M acetic... 

Inasmuch as extensive maleylation of free amino groups did not abolish the hemagglutinating and polysaccharide-precipitating activity of the lentil lectin, it is probable that amino groups are not involved in the carbohydrate-binding site of the lectin.4473 Treatment of the lentil lectin with 1-acetylimidazole resulted in the modification of 3-5 tyrosyl and 7-17 amino groups.4473 The modified proteins had lost their hemagglutinating activity, but retained their capacity to interact with polysaccharides and to bind to erythrocytes.4473... 

A comparative study of the hemagglutinating activities of the pea (Pisum sativum), the lentil (Lens culinaris), and the jack-bean (Canavalia ensiformis) lectins towards the erythrocytes of fourteen different species showed446 that the pea and lentil lectins were, in all instances, more active than con A. Of great interest was the finding that, among these three lectins, con A alone was completely inactive against human erythrocytes (blood group, unspecified).446... 

Animal tests have demonstrated that their toxicity often does not parallel hemagglutination activity. Thus, lectins from soybeans and garden beans are toxic, but not those from peas and lentils. These and other observations suggest that it is not the hemagglutination activity but other activities of lectins which are responsible for their toxicity. One toxic effect originates in the, at least partial. 

---