3iq3

Structural highlights

Function

PA2H1_BOTJR Snake venom phospholipase A2 homolog that lacks enzymatic activity. Shows local myotoxic activity (PubMed:11018293, PubMed:12079495, PubMed:31906173). Induces inflammation, since it induces edema and leukocytes infiltration (PubMed:11018293, PubMed:31906173). In addition, it induces NLRP3 NLRP3, ASC (PYCARD), caspase-1 (CASP1), and IL-1beta (IL1B) gene expression in the gastrocnemius muscle, showing that it is able to activate NLRP3 inflammasome (PubMed:31906173). It also damages artificial and myoblast membranes by a calcium-independent mechanism, has bactericidal activity, and induces neuromuscular blockade (PubMed:27531710). A model of myotoxic mechanism has been proposed: an apo Lys49-PLA2 is activated by the entrance of a hydrophobic molecule (e.g. fatty acid) at the hydrophobic channel of the protein leading to a reorientation of a monomer (PubMed:27531710) (By similarity). This reorientation causes a transition between 'inactive' to 'active' states, causing alignment of C-terminal and membrane-docking sites (MDoS) side-by-side and putting the membrane-disruption sites (MDiS) in the same plane, exposed to solvent and in a symmetric position for both monomers (PubMed:27531710) (By similarity). The MDoS region stabilizes the toxin on membrane by the interaction of charged residues with phospholipid head groups (PubMed:27531710) (By similarity). Subsequently, the MDiS region destabilizes the membrane with penetration of hydrophobic residues (PubMed:27531710) (By similarity). This insertion causes a disorganization of the membrane, allowing an uncontrolled influx of ions (i.e. calcium and sodium), and eventually triggering irreversible intracellular alterations and cell death (PubMed:27531710) (By similarity).[UniProtKB:I6L8L6]^{[1] [2] [3] [4] [5] [6] [7] [8] [9]}

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

See Also

• Phospholipase A2 3D structures
• Phospholipase A2 homolog

References

1. ↑ 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
2. ↑ 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
3. ↑ 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
4. ↑ 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
5. ↑ 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
6. ↑ 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
7. ↑ Borges RJ, Cardoso FF, Fernandes CA, Dreyer TR, de Moraes DS, Floriano RS, Rodrigues-Simioni L, Fontes MR. Functional and structural studies of a Phospholipase A2-like protein complexed to zinc ions: Insights on its myotoxicity and inhibition mechanism. Biochim Biophys Acta. 2017 Jan;1861(1 Pt A):3199-3209. doi:, 10.1016/j.bbagen.2016.08.003. Epub 2016 Aug 13. PMID:27531710 doi:http://dx.doi.org/10.1016/j.bbagen.2016.08.003
8. ↑ 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
9. ↑ Boeno CN, Paloschi MV, Lopes JA, Pires WL, Setubal SDS, Evangelista JR, Soares AM, Zuliani JP. Inflammasome Activation Induced by a Snake Venom Lys49-Phospholipase A2 Homologue. Toxins (Basel). 2019 Dec 31;12(1). pii: toxins12010022. doi:, 10.3390/toxins12010022. PMID:31906173 doi:http://dx.doi.org/10.3390/toxins12010022
10. ↑ 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