Interaction of Naja naja atra cardiotoxin 3 with H-trisaccharide modulates its hemolytic activity and membrane-damaging activity.
To address whether saccharide moieties of blood groups A, B and O antigens modulate hemolytic activity of Naja naja atra cardiotoxins (CTXs), the present study was carried out. Unlike other CTX isotoxins, hemolytic activity of CTX3 toward blood group O cholesterol-depleted red blood cells (RBCs) was notably lower than that of blood groups A and B cholesterol-depleted RBCs. Conversion of blood group B RBCs into blood group O RBCs by alpha-galactosidase treatment attenuated the susceptibility for hemolytic activity of CTX3, suggesting that H-antigen affected hemolytic potency of CTX3. Pre-incubation with H-trisaccharide reduced hemolytic activity and membrane-damaging activity of CTX3. Moreover, CTX3 showed a higher binding capability with H-trisaccharide than other CTXs did. CD spectra showed that the binding with H-trisaccharide induced changes in gross conformation of CTX3. Self-quenching studies revealed that oligomerization of CTX3 was affected in the presence of H-trisaccharide. Taken together, our data suggest that the binding of CTX3 with H-antigen alters its membrane-bound mode, thus reducing its hemolytic activity toward blood group O cholesterol-depleted RBCs.
Kao
Pei-Hsiu
PH
Institute of Biomedical Sciences, National Sun Yat-Sen University-Kaohsiung Medical University Joint Research Center, National Sun Yat-Sen University, Kaohsiung 804, Taiwan.
Lin
Shinne-Ren
SR
Chang
Long-Sen
LS
D000818:Animals; D001789:Blood Group Antigens / Q000032:analysis; D001788:Blood Grouping and Crossmatching; D002942:Circular Dichroism; D004179:Cobra Cardiotoxin Proteins / Q000737:chemistry / Q000633:toxicity*; D017815:Elapidae / Q000378:metabolism*; D004910:Erythrocyte Membrane / Q000187:drug effects* / Q000648:ultrastructure; D004912:Erythrocytes / Q000187:drug effects; D005456:Fluorescent Dyes; D006461:Hemolysis / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D008081:Liposomes / Q000737:chemistry; D008958:Models, Molecular; D020112:Rhodamine 123; D014312:Trisaccharides / Q000737:chemistry*; D000519:alpha-Galactosidase / Q000737:chemistry
D001789:Blood Group Antigens; D004179:Cobra Cardiotoxin Proteins; D005456:Fluorescent Dyes; D008081:Liposomes; D014312:Trisaccharides; C082202:cardiotoxin III, Naja naja atra; D020112:Rhodamine 123; D000519:alpha-Galactosidase