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 N-glycosylation 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 post-translational processes play a major role in shaping venom phenotypes.

中文翻译：

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岛屿物种Batrops alcatraz的毒液分析：使用底物的胺同位素同位素标记对蛋白质组，糖蛋白组和N末端组进行表征

矛头恶魔，特有的Alcatrazes群岛的物种，被认为是极度濒危由于发生了小面积和其栖息地的质量下降。我们最近报道了鉴定附在Bothrops物种毒素上的N-聚糖的方法，表明在Jararaca B. jararaca复合体（B. jararaca，B。insularis和B. alcatraz）的毒液中有相似的成分。在这里，我们使用电泳，蛋白质组学和糖蛋白组学方法表征恶臭芽孢杆菌的毒液。电泳显示恶臭双歧杆菌毒液与jararaca B. insularis和B. jararaca不同; 然而，N-糖基的去除揭示了它们之间的相似性，这表明N-糖基化位点的占据有助于B. jararaca复合物的种间变异。金属蛋白酶是恶性芽孢杆菌毒液蛋白质组中鉴定的主要毒素类别，其次是丝氨酸蛋白酶和C型凝集素，总的说来，成年的恶臭芽孢杆菌毒液类似于jararaca幼体标本。的比较glycoproteomic分析B.恶魔毒液与B. jararaca和B. insularis指出在不同毒素类别之间，N-糖基化基序的利用可能有所不同。此外，我们首次使用底物的末端胺同位素标记法（TAILS）探查了蛇毒的N端，并报告了〜30％的N-末端对应于截短的毒素形式和〜37％的N恶性芽孢杆菌毒液中焦谷氨酸阻断的末端序列。这些发现强调了蛇毒腺转录组和蛋白质组之间的低相关性，并支持了翻译后过程在塑造蛇毒表型中起主要作用的观点。