Back to Search
Start Over
The Amino Acid Sequence of Bothropstoxin-II, an Asp-49 Myotoxin from Bothrops jararacussu (Jararacucu) Venom with Low Phospholipase A2 Activity.
- Source :
- Journal of Protein Chemistry; May1998, Vol. 17 Issue 4, p381-386, 6p
- Publication Year :
- 1998
-
Abstract
- The complete amino acid sequence of bothropstoxin-II (BthTX-II), a myotoxin isolated from Bothrops jararacussu snake venom, is reported. The results show that BthTX-II is an Asp-49 phospholipase A<subscript>2</subscript> (PLA<subscript>2</subscript>)-like protein composed of a single polypeptide chain of 120 amino acid residues ( M<subscript>r</subscript> = 13,976), containing one methionine and 14 half-cystines. Despite a high degree of homology with other PLA<subscript>2</subscript>'s and the presence of the strategic residues known to compose the Ca<superscript>2+</superscript>-binding loop, namely Tyr-28, Gly-30, Gly-32, and especially Asp-49, besides His-48, Tyr-52, and Asp-99, all of them directly or indirectly involved in catalysis, BthTX-II revealed a very low PLA<subscript>2</subscript> activity when assayed on egg yolk phosphatidylcholine. We attribute this low catalytic activity to the existence of extra mutations, e.g., Trp-5 for Phe-5, which points to the need of considering other strategic positions, since only Lys-49 PLA<subscript>2</subscript>'s have been considered to be devoid of this enzymatic activity. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 02778033
- Volume :
- 17
- Issue :
- 4
- Database :
- Complementary Index
- Journal :
- Journal of Protein Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 50172268
- Full Text :
- https://doi.org/10.1023/A:1022563401413