Molecular cloning, functional expression, and characterization of isolectin genes of hemolytic lectin CEL-III from the marine invertebrate Cucumaria echinata.
CEL-III is a hemolytic lectin purified from the marine invertebrate Cucumaria echinata. Previous research has indictated that CEL-III is composed of several isoforms. Here we identified five CEL-III isolectin genes, designated CEL-III-L1, CEL-III-L2, CEL-III-S1, CEL-III-S2, and CEL-III-LS1, by cDNA cloning. The deduced amino acid sequences suggested they shared 94.0-99.8% identical residues. Among the amino acid residues involved in carbohydrate binding, the His residue, which contributes to stacking with sugar, in subdomain 1α was replaced by Tyr in CEL-III-L2. The recombinant proteins were expressed in Escherichia coli or insect cells. rCEL-III-L2 showed higher hemolytic activity than those of the other isolectins. Furthermore, an apparent oligomer band of rCEL-III-L2 was detected on erythrocyte membranes, although the other isolectins showed smear bands. These results suggest that Tyr36 of CEL-III-L2 is important for the expression of hemolytic activity and oligomerization.
Laboratory of Food Molecular Functionality, College of Agriculture, Ibaraki University, Ibaraki, Japan.
Yoshiki
Y
Shimizu
Hiroshi
H
Yamazaki
Shigeto
S
Yoshida
Masami
M
Yonekura
Yoshiaki
Y
Kouzuma
D000818:Animals; D003001:Cloning, Molecular; D048016:Cucumaria / Q000737:chemistry* / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004910:Erythrocyte Membrane; D006461:Hemolysis; D053878:Hemolytic Agents; D006801:Humans; D007448:Invertebrates; D037102:Lectins / Q000235:genetics* / Q000502:physiology; D008386:Marine Biology; D011994:Recombinant Proteins / Q000096:biosynthesis
C402644:CEL-III lectin, Cucumaria echinata; D018076:DNA, Complementary; D053878:Hemolytic Agents; D037102:Lectins; D011994:Recombinant Proteins