| Author/Editor | Čurin-Šerbec, V | |
| Title | Študij toksičnega mesta na amoditoksinu A s pomočjo monoklonskih protiteles | |
| Type | monografija | |
| Place | Ljubljana | |
| Publisher | Fakulteta za naravoslovje in tehnologijo | |
| Publication year | 1991 | |
| Volume | str. 99 | |
| Language | slo | |
| Abstract | Ammodytoxin A, formerly designated as the venom fraction "k2", is the most basic and the most toxic phospholipase A2 from the venom of the long-nosed viper, Vipera ammodytes amodytes (i.v. LD5o=0,21 mg/kg). It is 28-times more lethal than ammodytoxin B (i.v. LD5o= mg.kg) and 17-times more lethal than ammodytoxin C (i.v. LD5o=0,36 mg/kg). Ali sequenced ammodytoxins are composed of 122 amino acids. Ammodytoxins A and B differ in only three amino acids at the positions 115, 118 and 119, whereas ammodytoxins A and C differ in two acid residues at the positions 124 and 128. Sequential data provided some evidence for the localization of the toxic site in ammodytoxin which disagrees with the predictions of this site in presinaptically active phospholipases. We decided to elucidate the toxic site of ammodytoxin A molecule by monoclonal antibodies produced against four synthetic peptides coupled to a carrier protein. Peptides L1, L2, L3 and L4 were chosen from the known primary structure of ammodytoxin A. L1 comprises all three structural differences between ammodytoxins A and B, and L3 are peptides, where several basic amino acids beleived to be responsible for the toxicity, are located, whereas L4 comprises two differences in the primary structure of ammodytoxins A and C. Monoclonal antibodies against all four peptides were purified and their Kd values were determined. To reduce possible steric hindrance, which may influence the lethality of complexes antibody-antigen, Fab fragments of anti-L1, anti-L2 and anti-L3 monoclonal antibodies were prepared. Relative PLA2 activity and toxicity of complexes of ammodytoxin A with these monoclonal antibodies and their Fab fragments were also determined and the effect of some complexes on neuromuscular junction was measured. The results are in agreement with our previous data, obtained with polyclonal antibodies against all four peptides.(Abstract truncated) | |
| Descriptors | VIPER VENOMS PHOSPHOLIPASES A ANTIBODIES, MONOCLONAL PEPTIDES AMINO ACID SEQUENCE MICE, INBRED BALB C NEUROMUSCULAR JUNCTION |