Venom Profiling of the Insular Species Bothrops alcatraz: Characterization of Proteome, Glycoproteome, and N-Terminome Using Terminal Amine Isotopic Labeling of Substrates

Abstract

Bothrops alcatraz, a species endemic to Alcatrazes Islands, is regarded as critically endangered due to its small area of occurrence and the declining quality of its habitat. We recently reported the identification of N-glycans attached to toxins of Bothrops species, showing similar compositions in venoms of the B. jararaca complex (B. jararaca, B. insularis, and B. alcatraz). Here, we characterized B. alcatraz venom using electrophoretic, proteomic, and glycoproteomic approaches. Electrophoresis showed that B. alcatraz venom differs from B. jararaca and B. insularis; however, N-glycan removal revealed similarities between them, indicating that the occupation of N-glycosylation sites contributes to interspecies variability in the B. jararaca complex. Metalloproteinase was the major toxin class identified in the B. alcatraz venom proteome followed by serine proteinase and C-type lectin, and overall, the adult B. alcatraz venom resembles that of B. jararaca juvenile specimens. The comparative glycoproteomic analysis of B. alcatraz venom with B. jararaca and B. insularis indicated that there may be differences in the utilization of Nglycosylation motifs among their different toxin classes. Furthermore, we prospected for the first time the N-terminome of a snake venom using the terminal amine isotopic labeling of substrates (TAILS) approach and report the presence of ∼30% of N-termini corresponding to truncated toxin forms and ∼37% N-terminal sequences blocked by pyroglutamic acid in B. alcatraz venom. These findings underscore a low correlation between venom gland transcriptomes and proteomes and support the view that posttranslational processes play a major role in shaping venom phenotypes.

Venom Composition of Neglected Bothropoid Snakes from the Amazon Rainforest: Ecological and Toxinological Implications

“…The presence of K49-PLA 2 homologs has also been reported in proteomes of Bothrocophias campbelli [ 26 ] and Bothrocophias myersi [ 25 ] venoms. Thus, we attempted to search the spectra generated in the LC-MS/MS using the B. hyoprora venom pool against a comprehensive databank comprising 111,653 sequences from snake venom-related proteins [ 44 ]; and even in this search, K49-PLA 2 isoforms were not detected in the B. hyoprora venom proteome, evidencing their absence in the venom of B. hyoprora from Acre.…”

Comparative venomic profiles of three spiders of the genus Phoneutria

“…Intraspecific differences in animal venom composition are frequently noticed and several factors have been shown to influence it, such as food availability, season, environment, stages of maturation, and sex of each specimen [ 20 , 21 ]. In addition, the post-translation process (proteolysis and C-terminal alterations) is a recurrent source for this intraspecific variability among venoms [ 68 , 71 ]. Besides, the variability among venoms of species from the same genus has also been described.…”

“…Besides, the variability among venoms of species from the same genus has also been described. This interspecific variability results in isoforms of the same toxin, with strong similarities in their structures and biological activities [ 21 , 71 ]. Furthermore, according to the literature, this venom variation can be highly useful as a marker to identify species [ 72 - 74 ].…”

Venenos de serpentes do gênero >i<Bothrops>/i<: impacto da glicosilação na complexidade dos proteomas e função de toxinas

“…Essa reação é considerada uma modificação pós-traducional importante, como por exemplo em peptídeos potenciadores de bradicinina e em algumas SVMPs [209][210][211][212] . A presença de GCT também foi relatada por Melani e colaboradores 213 , no proteoma do veneno Crotalus durissus terrificus, e também em venenos do gênero Bothrops 41,214 .…”