title: In vitro effects of Echis carinatus venom on the human plasma proteome.
abstract: Echis carinatus venom (EV) is a complex mixture of toxins that contribute to its lethality. EV proteolytic activity was analyzed by zymography, chromogenic assays, and SDS-PAGE. To understand the molecular mechanism of the envenomation, we investigated the in vitro effect of EV on human plasma proteins. We looked for EV protein substrates and their proteolytic fragments. We analyzed EV proteolytic activity on standard proteins such as prothrombin or fibrinogen. To set up the optimal EV:plasma protein ratio conditions, plasma was incubated with EV (treated plasma), depleted of abundant proteins, and subjected to SDS-PAGE. Samples from control and treated plasma were also analyzed by 2-DE/MALDI-TOF MS, leading to the identification of four classes of plasma proteins cleaved by EV: proteases, protease inhibitors, binding proteins, and transporters. EV mainly proteolyzes entire proteins but can also act on physiological fragments. In summary, the physiological effects of EV proteases involve other important processes in addition to blood coagulation; complement activation and hemoglobin metabolism are also affected. In particular, the cleavage of protease inhibitors appears to be the mechanism through which the venom neutralizes the body's defenses.
authors.affiliation: Department of Internal Medicine, Endocrine-Metabolic Sciences and Biochemistry, University of Siena, Siena, Italy. guerranti@unisi.it
authors.forename: Roberto
authors.initials: R
authors.lastname: Guerranti
authors.forename: Alessio
authors.initials: A
authors.lastname: Cortelazzo
authors.forename: Nnadozie S
authors.initials: NS
authors.lastname: Hope-Onyekwere
authors.forename: Emiliano
authors.initials: E
authors.lastname: Furlani
authors.forename: Helena
authors.initials: H
authors.lastname: Cerutti
authors.forename: Michele
authors.initials: M
authors.lastname: Puglia
authors.forename: Luca
authors.initials: L
authors.lastname: Bini
authors.forename: Roberto
authors.initials: R
authors.lastname: Leoncini
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000737:chemistry / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis; D020543:Proteome / Q000032:analysis / Q000187:drug effects; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods; D014757:Viper Venoms / Q000737:chemistry / Q000494:pharmacology; D017819:Viperidae
chemical_list: D001798:Blood Proteins; D010455:Peptides; D020543:Proteome; D014757:Viper Venoms