当前位置： SCI文献检索 > BIOCHEMISTRY期刊下所有文献 > Structure-function relationships of scorpion neurotoxins.

Structure-function relationships of scorpion neurotoxins.

Abstract：

:Chemical modification of some trifunctional amino acid residues in toxins I, II, and III of the scorpion Androctonus australis Hector have been performed. The results indicate: (1) Reduction and methylation of one disulfide bridge destroy toxic activity of toxin II. (2) The only tryptophan residue of toxin II (position 38) is not included in the active site of the molecule. (3) Modification of five carboxylates out of the seven contained in toxin II suppresses the toxic activity. (4) Acetylation of the lysine and tyrosine residues in toxin II leads to the loss of both toxic and antigenic activity. Treatment of the acetylated toxin by hydroxylamine restores partially the antigenic activity. In the case of toxin I, total acetylation abolishes only the toxic activity. It is concluded that at least one tyrosine residue must be involved in an antigenic site of toxin II. (5) Citraconylation of toxins II and III leads to complete loss of toxicity; decitraconylation restores full activity. (6) Guanidination of toxin II does not affect its toxicity significantly. (7) Alkylation of toxin II by iodoacetic acid affects both amino groups and histidine residues. The loss of toxicity is mainly due to the modification of the lysine residues. In the case of toxin I, the kinetics of toxicity loss closely parallel the covalent modification of one lysine residue.

journal_name

Biochemistry

journal_title

Biochemistry

authors

Habersetzer-Rochat C,Sampieri F

doi

10.1021/bi00656a002

subject

Has Abstract

pub_date

1976-06-01 00:00:00

pages

2254-61

issue

11

eissn

0006-2960

issn

1520-4995

journal_volume

15

pub_type

杂志文章

相关文献

BIOCHEMISTRY文献大全