| Structural highlights
Function
[PA2B1_BOTJR] Snake venom phospholipase A2 homolog that lacks enzymatic activity. In vivo, induces muscle necrosis, accompanied by polymorphonuclear cell infiltration, and edema in the mouse paw. Damages artificial and myoblast membranes by a calcium-independent mechanism. Has bactericidal activity.[1] [2] [3] [4] [5] [6] [7]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Phospholipases A(2) (Asp49-PLA(2)s) are enzymes responsible for cellular membrane disruption through Ca(2+)-dependent hydrolysis of phospholipids. A class of these proteins (Lys49-PLA(2)s) does not show catalytic activity but can exert a pronounced local myotoxic effect that is not neutralized by serum therapy. In this work, we present five structures of Lys49-PLA(2)s from snakes of the Bothrops genus in apo form, complexed with PEG molecules and chemically modified by p-bromofenacil bromide (BPB), a classic inhibitor of PLA(2). We present herein an extensive structural analysis including: (i) the function of hydrophobic long-chain molecules as Lys49-PLA(2)s inhibitors, (ii) the role of Lys122, previously indicated as being responsible for Lys49-PLA(2)s catalytic inactivity and, (iii) a structural comparison of the Ca(2+)-binding loop region between Lys49 and Asp49-PLA(2)s. The Lys122 analysis of 30 different monomers for apo and complexed Lys49-PLA(2)s structures shows that this residue is very flexible and may bind to different carboxyl groups giving stability to the crystal structures. The structural comparisons of the Ca(2+)-binding loop region between Lys49 and Asp49-PLA(2)s reveal the importance of the Tyr28 residue conservation in Asp49-PLA(2)s to the integrity of this loop. The Tyr28 residue stabilizes this region by an interaction with Gly35 residue. In Lys49-PLA(2)s and low-catalytic Asp49-PLA(2)s this interaction does not occur, preventing the binding of Ca(2+).
Comparison between apo and complexed structures of bothropstoxin-I reveals the role of Lys122 and Ca(2+)-binding loop region for the catalytically inactive Lys49-PLA(2)s.,Fernandes CA, Marchi-Salvador DP, Salvador GM, Silva MC, Costa TR, Soares AM, Fontes MR J Struct Biol. 2010 Apr 4. PMID:20371382[8]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Homsi-Brandeburgo MI, Queiroz LS, Santo-Neto H, Rodrigues-Simioni L, Giglio JR. Fractionation of Bothrops jararacussu snake venom: partial chemical characterization and biological activity of bothropstoxin. Toxicon. 1988;26(7):615-27. PMID:3176051
- ↑ Andriao-Escarso SH, Soares AM, Rodrigues VM, Angulo Y, Diaz C, Lomonte B, Gutierrez JM, Giglio JR. Myotoxic phospholipases A(2) in bothrops snake venoms: effect of chemical modifications on the enzymatic and pharmacological properties of bothropstoxins from Bothrops jararacussu. Biochimie. 2000 Aug;82(8):755-63. PMID:11018293
- ↑ Ward RJ, Chioato L, de Oliveira AH, Ruller R, Sa JM. Active-site mutagenesis of a Lys49-phospholipase A2: biological and membrane-disrupting activities in the absence of catalysis. Biochem J. 2002 Feb 15;362(Pt 1):89-96. PMID:11829743
- ↑ Chioato L, De Oliveira AH, Ruller R, Sa JM, Ward RJ. Distinct sites for myotoxic and membrane-damaging activities in the C-terminal region of a Lys49-phospholipase A2. Biochem J. 2002 Sep 15;366(Pt 3):971-6. PMID:12079495 doi:http://dx.doi.org/10.1042/BJ20020092
- ↑ Chioato L, Aragao EA, Lopes Ferreira T, Medeiros AI, Faccioli LH, Ward RJ. Mapping of the structural determinants of artificial and biological membrane damaging activities of a Lys49 phospholipase A2 by scanning alanine mutagenesis. Biochim Biophys Acta. 2007 May;1768(5):1247-57. Epub 2007 Feb 9. PMID:17346668 doi:http://dx.doi.org/10.1016/j.bbamem.2007.01.023
- ↑ Aragao EA, Chioato L, Ward RJ. Permeabilization of E. coli K12 inner and outer membranes by bothropstoxin-I, A LYS49 phospholipase A2 from Bothrops jararacussu. Toxicon. 2008 Mar 15;51(4):538-46. Epub 2007 Nov 17. PMID:18160090 doi:http://dx.doi.org/10.1016/j.toxicon.2007.11.004
- ↑ Murakami MT, Vicoti MM, Abrego JR, Lourenzoni MR, Cintra AC, Arruda EZ, Tomaz MA, Melo PA, Arni RK. Interfacial surface charge and free accessibility to the PLA2-active site-like region are essential requirements for the activity of Lys49 PLA2 homologues. Toxicon. 2007 Mar 1;49(3):378-87. Epub 2006 Nov 3. PMID:17157889 doi:10.1016/j.toxicon.2006.10.011
- ↑ Fernandes CA, Marchi-Salvador DP, Salvador GM, Silva MC, Costa TR, Soares AM, Fontes MR. Comparison between apo and complexed structures of bothropstoxin-I reveals the role of Lys122 and Ca(2+)-binding loop region for the catalytically inactive Lys49-PLA(2)s. J Struct Biol. 2010 Apr 4. PMID:20371382 doi:10.1016/j.jsb.2010.03.019
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