title: Isolation, functional characterization and proteomic identification of CC2-PLA₂ from Cerastes cerastes venom: a basic platelet-aggregation-inhibiting factor.
abstract: Three-step chromatography and proteomic analysis have been used to purify and characterize a new basic phospholipase A₂ named CC2-PLA₂ from the venom of Cerastes cerastes. This phospholipase A₂ has been isolated to an extent of about 50-folds and its molecular weight was estimated at 13,534 Da. For CC2-PLA₂ identification and LC-MALDI-MS/MS analysis, the protein was reduced, alkylated and double hydrolyzed by lysine-C endopeptidase and trypsin. Tryptic fragments of LC-MS/MS analyzed CC2-PLA₂ showed sequence similarities with other snake venom PLA₂. This presents only 51 % (61/120 amino acid residues) sequence homology with the first PLA₂ (gi |129506|) previously purified from the same venom. The isolated CC2-PLA₂ displayed anti-aggregative effect on platelets and induced an inflammatory response characterized by leukocytosis in the peripheral blood. This inflammatory response is accompanied by a release of inflammatory mediators such as IL-6, eosinophil peroxidase and complement system. Obtained results indicate that CC2-PLA₂ induced a release of high level of pro-inflammatory (IL-6) cytokine and no effect on the level of anti-inflammatory cytokine (IL-10) in blood sera. Furthermore, eosinophil peroxidase activity and hemolytic complement effect increased in peripheral blood. Mononuclear and neutrophil cells were found predominant in the induced leucocytosis following CC2-PLA₂ administration into animals.
authors.affiliation: USTHB, Laboratory of Cellular and Molecular Biology, Faculty of Biological Sciences, USTHB, BP 32, El-Alia, Bab Ezzouar, Algiers, Algeria.
authors.forename: Fatah
authors.initials: F
authors.lastname: Chérifi
authors.forename: Abdelkader
authors.initials: A
authors.lastname: Namane
authors.forename: Fatima
authors.initials: F
authors.lastname: Laraba-Djebari
mesh_terms: D000818:Animals; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D056827:Endosomal Sorting Complexes Required for Transport / Q000737:chemistry* / Q000378:metabolism; D016753:Interleukin-10 / Q000737:chemistry / Q000378:metabolism; D054467:Phospholipases A2 / Q000737:chemistry* / Q000378:metabolism; D010972:Platelet Activating Factor / Q000737:chemistry* / Q000378:metabolism; D040901:Proteomics; D053719:Tandem Mass Spectrometry; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism; D014757:Viper Venoms / Q000737:chemistry*; D017819:Viperidae / Q000378:metabolism; D000099177:Tsg101 Protein
chemical_list: D004268:DNA-Binding Proteins; D056827:Endosomal Sorting Complexes Required for Transport; D016753:Interleukin-10; D054467:Phospholipases A2; D010972:Platelet Activating Factor; D014157:Transcription Factors; D014757:Viper Venoms; D000099177:Tsg101 Protein