title: [A modification of neurotoxin RTX-III from Radianthus macrodactylus actinin with acetic anhydride].
abstract: Upon modification of neurotoxin RTX-III at amino groups with [3H]acetic anhydride, four monoacetyl and four diacetyl derivatives have been obtained. Acetylation of the N-terminal amino group led to 12-fold decrease of toxicity in mice. Monoderivatives of the toxin with either Lys or two out of three C-terminal Lys residues modified showed a 2-fold drop in toxicity as compared with the native RTX-III. Diacetylation caused a 30 to 35-fold decrease in toxicity, the N-terminal amino group being modified in all the derivatives. As assessed by circular dichroism method, the modification of amino groups, except for N-terminal one, affected secondary structure of the toxin. The data suggest the N-terminal amino group to be essential for toxicity of RTX-III.
authors.forename: V M
authors.initials: VM
authors.lastname: Makhnyr'
authors.forename: E P
authors.initials: EP
authors.lastname: Kozlovskaia
mesh_terms: D000089:Acetic Anhydrides; D000185:Actinin; D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D003063:Cnidaria; D003064:Cnidarian Venoms; D007202:Indicators and Reagents; D008969:Molecular Sequence Data; D015202:Protein Engineering; D012615:Sea Anemones
chemical_list: D000089:Acetic Anhydrides; D003064:Cnidarian Venoms; D007202:Indicators and Reagents; D000185:Actinin; C032104:toxin III (Anemonia sulcata)
vernacular_title: Modifikatsiia neurotoksina RTX-III iz aktinin Radianthus macrodactylus ukusnym angidridom.