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Titolo:
Purification, characterization, and primary structure of four depressant insect-selective neurotoxin analogs from scorpion (Buthus sindicus) venom
Autore:
Ali, SA; Stoeva, S; Grossmann, JG; Abbasi, A; Voelter, W;
Indirizzi:
Univ Tubingen, Inst Physiol Chem, Phys Biochem Abt, D-72076 Tubingen, Germany Univ Tubingen Tubingen Germany D-72076 em Abt, D-72076 Tubingen, Germany Univ Karachi, HEJ Res Inst Chem, Int Ctr Chem Sci, Karachi 75270, PakistanUniv Karachi Karachi Pakistan 75270 tr Chem Sci, Karachi 75270, Pakistan CCLRC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England CCLRC Warrington Cheshire England WA4 4AD gton WA4 4AD, Cheshire, England
Titolo Testata:
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
fascicolo: 2, volume: 391, anno: 2001,
pagine: 197 - 206
SICI:
0003-9861(20010715)391:2<197:PCAPSO>2.0.ZU;2-J
Fonte:
ISI
Lingua:
ENG
Soggetto:
ANDROCTONUS-AUSTRALIS-HECTOR; LEIURUS-QUINQUESTRIATUS-QUINQUESTRIATUS; SODIUM CURRENT INACTIVATION; RECEPTOR-SITES; TITYUS-SERRULATUS; ANTIINSECT TOXIN; CENTRUROIDES-NOXIUS; MARTENSII KARSCH; RAT-BRAIN; CHANNELS;
Keywords:
amino acid sequence; mass spectrometry; depressant insect-selective neurotoxin; long-chain neurotoxins; sodium channel; scorpion; venom;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
49
Recensione:
Indirizzi per estratti:
Indirizzo: Ali, SA Univ Tubingen, Inst Physiol Chem, Phys Biochem Abt, Hoppe Seyler Str 4, D-72076 Tubingen, Germany Univ Tubingen Hoppe Seyler Str 4 Tubingen Germany D-72076 Germany
Citazione:
S.A. Ali et al., "Purification, characterization, and primary structure of four depressant insect-selective neurotoxin analogs from scorpion (Buthus sindicus) venom", ARCH BIOCH, 391(2), 2001, pp. 197-206

Abstract

Four depressant insect-selective neurotoxin analogs (termed Bs-dprIT1 to 4) from the venom of the scorpion Buthus sindicus were purified to homogeneity in a single step using reverse-phase HPLC. The molecular masses of the purified toxins were 6820.9, 6892.4, 6714.7, and 6657.1 Da, respectively, asdetermined by mass spectrometry. These long-chain neurotoxins were potent against insects with half lethal dose values of 67, 81, 103, and 78 ng/100 mg larva and 138, 160, 163, and 142 ng/100 mg cockroach, respectively, but were not lethal to mice even at the highest applied dose of 10 mug/20 g mouse. When injected into blowfly larvae (Sarcophoga falculata), Bs-dprIT1 to 4 induced classical manifestations of depressant toxins, i.e., a slow depressant flaccid paralysis. The primary structures of Bs-dprIT 1 to 4 revealedhigh sequence homology (60-75%) with other depressant insect toxins isolated from scorpion venoms. Despite the high sequence conservation, Bs-dprIT1 to 4 showed some remarkable features such as (i) the presence of methionine(Met(6) in Bs-dprIT1 and Met(24) in Bs-dprIT2 to 4) and histidine (His(58)and His(57) in Bs-dprIT1) residues, i.e., amino acid residues that are uncommon to this type of toxin; (ii) the substitution of two highly conserved tryptophan residues (Trp43 --> Ala and Trp53 --> His) in the sequence of Bs-dprIT1; and (iii) the occurrence of more positively charged amino acid residues at the C-terminal end than in other depressant insect toxins. Multiple sequence alignment, sequence analysis, sequence-based structure prediction, and 3D homology modeling studies revealed a protein fold and secondary structural elements similar to those of other scorpion toxins affecting sodium channel activation. The electrostatic potential calculated on the surface of the predicted 3D model of Bs-dprIT1 revealed a significant positive patch in the region of the toxin that is supposed to bind to the sodium channel. (C) 2001 Academic Press.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/11/20 alle ore 15:05:45