Chapeaurouge Alex, Reza Md Abu, Mackessy Stephen P, Carvalho Paulo C, Valente Richard H, Teixeira-Ferreira André, Perales Jonas, Lin Qingsong, Kini R Manjunatha
Laboratório de Toxinologia, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro, RJ, 21045-900, Brazil; Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, Singapore, 117543, Singapore.
Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, Singapore, 117543, Singapore.
PLoS One. 2015 May 8;10(5):e0092091. doi: 10.1371/journal.pone.0092091. eCollection 2015.
The complete sequence characterization of snake venom proteins by mass spectrometry is rather challenging due to the presence of multiple isoforms from different protein families. In the present study, we investigated the tryptic digest of the venom of the viperid snake Sistrurus catenatus edwardsii by a combined approach of liquid chromatography coupled to either electrospray (online) or MALDI (offline) mass spectrometry. These different ionization techniques proved to be complementary allowing the identification a great variety of isoforms of diverse snake venom protein families, as evidenced by the detection of the corresponding unique peptides. For example, ten out of eleven predicted isoforms of serine proteinases of the venom of S. c. edwardsii were distinguished using this approach. Moreover, snake venom protein families not encountered in a previous transcriptome study of the venom gland of this snake were identified. In essence, our results support the notion that complementary ionization techniques of mass spectrometry allow for the detection of even subtle sequence differences of snake venom proteins, which is fundamental for future structure-function relationship and possible drug design studies.
由于存在来自不同蛋白质家族的多种异构体，通过质谱对蛇毒蛋白进行完整的序列表征颇具挑战性。在本研究中，我们采用液相色谱与电喷雾（在线）或基质辅助激光解吸电离（离线）质谱联用的方法，研究了蝰蛇科蛇种爱德华氏珠斑锦蛇毒液的胰蛋白酶消化产物。事实证明，这些不同的电离技术具有互补性，能够鉴定出多种蛇毒蛋白家族的多种异构体，相应独特肽段的检测即为明证。例如，利用该方法区分出了爱德华氏珠斑锦蛇毒液中丝氨酸蛋白酶11种预测异构体中的10种。此外，还鉴定出了此前对该蛇毒腺进行转录组研究时未发现的蛇毒蛋白家族。从本质上讲，我们的结果支持这样一种观点，即质谱的互补电离技术能够检测出蛇毒蛋白中哪怕是细微的序列差异，这对于未来的结构-功能关系研究以及可能的药物设计研究至关重要。
