Structure-Activity Relationship of Chlorotoxin-Like Peptides
AbstractAnimal venom (e.g., scorpion) is a rich source of various protein and peptide toxins with diverse physio-/pharmaco-logical activities, which generally exert their action via target-specific modulation of different ion channel functions. Scorpion venoms are among the most widely-known source of peptidyl neurotoxins used for callipering different ion channels, such as; Na+, K+, Ca+, Cl−, etc. A new peptide of the chlorotoxin family (i.e., Bs-Tx7) has been isolated, sequenced and synthesized from scorpion Buthus sindicus (family Buthidae) venom. This peptide demonstrates 66% with chlorotoxin (ClTx) and 82% with CFTR channel inhibitor (GaTx1) sequence identities reported from Leiurus quinquestriatus hebraeus venom. The toxin has a molecular mass of 3821 Da and possesses four intra-chain disulphide bonds. Amino acid sequence analysis of Bs-Tx7 revealed the presence of a scissile peptide bond (i.e., Gly-Ile) for human MMP2, whose activity is increased in the case of tumour malignancy. The effect of hMMP2 on Bs-Tx7, or vice versa, observed using the FRET peptide substrate with methoxycoumarin (Mca)/dinitrophenyl (Dnp) as fluorophore/quencher, designed and synthesized to obtain the lowest Km value for this substrate, showed approximately a 60% increase in the activity of hMMP2 upon incubation of Bs-Tx7 with the enzyme at a micromolar concentration (4 µM), indicating the importance of this toxin in diseases associated with decreased MMP2 activity. View Full-Text
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Ali, S.A.; Alam, M.; Abbasi, A.; Undheim, E.A.B.; Fry, B.G.; Kalbacher, H.; Voelter, W. Structure-Activity Relationship of Chlorotoxin-Like Peptides. Toxins 2016, 8, 36.
Ali SA, Alam M, Abbasi A, Undheim EAB, Fry BG, Kalbacher H, Voelter W. Structure-Activity Relationship of Chlorotoxin-Like Peptides. Toxins. 2016; 8(2):36.Chicago/Turabian Style
Ali, Syed A.; Alam, Mehtab; Abbasi, Atiya; Undheim, Eivind A.B.; Fry, Bryan G.; Kalbacher, Hubert; Voelter, Wolfgang. 2016. "Structure-Activity Relationship of Chlorotoxin-Like Peptides." Toxins 8, no. 2: 36.
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