Modulation of phospholipase A 2 activity generated by molecular evolution
| Autor: | Nicolay Genov, Tej P. Singh, Ch. Betzel, K. R. Rajashankar |
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| Rok vydání: | 1999 |
| Předmět: |
Models
Molecular Protein Conformation Molecular Sequence Data Neurotoxins Venom Viper Venoms Crystallography X-Ray complex mixtures Catalysis Phospholipases A Evolution Molecular Cellular and Molecular Neuroscience Phospholipase A2 Molecular evolution Viperidae biology.animal Enzyme Stability Animals Amino Acid Sequence Molecular Biology Pharmacology biology Vipera ammodytes Biological activity Cell Biology biology.organism_classification Divergent evolution Phospholipases A2 Biochemistry Snake venom biology.protein Molecular Medicine lipids (amino acids peptides and proteins) Sequence Alignment |
| Zdroj: | Cellular and Molecular Life Sciences (CMLS). 56:384-397 |
| ISSN: | 1420-9071 1420-682X |
| DOI: | 10.1007/s000180050440 |
| Popis: | Snake venom oligomeric neurotoxins offer several unique examples of modulation of phospholipase A2 (PLA2) activity generated by molecular evolution. This phenomenon was found in evolutionary younger snakes and is probably common for representatives of the genus Vipera. At present, the best-studied example is the heterodimeric neurotoxin vipoxin from the venom of the southeast European snake Vipera ammodytes meridionalis. It is a complex between a basic strongly toxic PLA2 and an acidic and catalytically inactive PLA2-like component (Inh). This is the first reported example of a high degree of structural homology (62%) between an enzyme and its natural protein inhibitor. The inhibitor is a product of the divergent evolution of the unstable PLA2 in order to stabilize it and to preserve the pharmacological activity/toxicity for a long time. Inh reduces both the catalytic activity and toxicity of PLA2. Vipoxin also illustrates evolution of the catalytic into a inhibitory function. Vipoxin analogues have been found in the venom of viperid snakes inhabiting diverse regions of the world. An attempt is made to explain modulation of the toxic function by the three-dimensional structure of vipoxin. |
| Databáze: | OpenAIRE |
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