Screening of Lectins in Crab and Shrimp from Fujian Coast of China

Twelve species of crustacean from Fujian coast were examined for lectins with different animal erythrocytes. Serum extracts fromall of 12 species showed agglutinating activity against at least two types of the erythrocytes used, which revealed the existence of lectins in these species. There were five species ( Penaeus japonicus, Lophosquilla costata, Charybdis feriatus, Portunus pelagicus, Scylla serrata ) whose serums could agglutinate all the erythrocytes tested. The lowest serum protein concentration required to produce erythrocytes agglutination varied remarkably, ranging from 0.7 μg/mL to 8 080 μg/mL. The strongest activity was shown in the agglutination of rabbit erythrocyte by serum of Penaeus vanaminas. Inhibition assays performed with seven mono- and bisaccharides showed that agglutination of quail erythrocytes by serums of three species (Portunus pelagicus, Scylla serrata and Sesarma sp. ) were not inhibited by any sugars, while others were inhibited by at least three types of sugars. The assay of temperature influence on agglutinating activity showed that only Penaeusjaponicus retained activity when the serum was heated to 90℃, and other serums lost their activity at 40 ℃, 50 ℃, 60 ℃, 70 ℃, 80 ℃ for 10 minutes, respectively.