[Toxin-binding activity of cyanogen bromide cleaved peptide fragments of the Chinese-cobra serum antitoxic protein].
OBJECTIVE
For further study of the structure-function relationship of the Chinese cobra serum antitoxic protein.


METHODS
Cyanogen bromide was used to cleave the peptide bonds which formed by the carboxyl group of Met residues. The cleaved products were ultrafiltrated to remove the small fragments below 10,000 and passed an affinity column packed with Sepharose-4B linked with cobrotoxin as ligand. The molecular weight and N-terminal amino acid residues of the cleaved peptide fragments bounded to the affinity column were then assayed.


RESULTS
The cleaved peptide fragments reserved toxin-binding activity were proved to be Lys2-Met485, Lys2-Met275, Lys276-Met485, Pro444-Met603.


CONCLUSIONS
This result revealed that all the three domains of CSAP, along the peptide chain, possess the toxin binding activity.
Chai
Y
Y
Department of Biochemistry, Medical College of Zhejiang University, Hangzhou 310031.
Shao
J
J
D000818:Animals; D002846:Chromatography, Affinity; D003039:Cobra Neurotoxin Proteins / Q000378:metabolism*; D003488:Cyanogen Bromide; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*
C082394:CSAP protein, Naja atra; D003039:Cobra Neurotoxin Proteins; D010446:Peptide Fragments; D011506:Proteins; D003488:Cyanogen Bromide