Top-down venomics of the East African green mamba, Dendroaspis angusticeps, and the black mamba, Dendroaspis polylepis, highlight the complexity of their toxin arsenals.
We report the characterization, by combination of high-resolution on-line molecular mass and disulfide bond profiling and top-down MS/MS analysis, of the venom proteomes of two congeneric African snake species of medical importance, Dendroaspis angusticeps (green mamba) and D. polylepis (black mamba). Each of these mamba venoms comprised more than two-hundred polypeptides belonging to just a few toxin families. Both venom proteomes are overwhelmingly composed of post-synaptically-acting short- and long-chain neurotoxins that potently inhibit muscle- and neuronal-type nicotinic acetylcholine receptors; muscarinic cardiotoxins; and dendrotoxins, that block some of the Kv1, n-class of K+ channels. However, the identity of the major proteins and their relative abundances exhibit marked interspecific variation. In addition, the greater resolution of the top-down venomic analytical approach revealed previously undetected protein species, isoforms and proteoforms, including the identification and precise location of modified lysine residues in a number of proteins in both venoms, but particularly in green mamba toxins. This comparative top-down venomic analysis unveiled the untapped complexity of Dendroaspis venoms and lays the foundations for rationalizing the notably different potency of green and black mamba lethal arsenals at locus resolution.



We report the characterization, by combination of high-resolution on-line molecular mass and disulfide bond profiling and top-down MS/MS analysis, of the venom proteomes of two congeneric African snake species of medical importance, Dendroaspis angusticeps (green mamba) and D. polylepis (black mamba). Each of these mamba venoms comprised more than two-hundred polypeptides belonging to just a few toxin families. Both venom proteomes are overwhelmingly composed of post-synaptically-acting short- and long-chain neurotoxins that potently inhibit muscle- and neuronal-type nicotinic acetylcholine receptors; muscarinic cardiotoxins; and dendrotoxins, that block some of the Kv1, n-class of K+ channels. However, the identity of the major proteins and their relative abundances exhibit marked interspecific variation. In addition, the greater resolution of the top-down venomic analytical approach revealed previously undetected protein species, isoforms and proteoforms, including the identification and precise location of modified lysine residues in a number of proteins in both venoms, but particularly in green mamba toxins. This comparative top-down venomic analysis unveiled the untapped complexity of Dendroaspis venoms and lays the foundations for rationalizing the notably different potency of green and black mamba lethal arsenals at locus resolution.
Technische Universität Berlin, Institut für Chemie, Berlin, Germany; University of California-San Diego, Skaggs School of Pharmacy & Pharmaceutical Sciences, La Jolla, CA, USA.
Daniel
D
Petras
Technische Universität Berlin, Institut für Chemie, Berlin, Germany.
Paul
P
Heiss
Alistair Reid Venom Research Unit, Liverpool, School of Tropical Medicine, Liverpool, United Kingdom.
Robert A
RA
Harrison
Technische Universität Berlin, Institut für Chemie, Berlin, Germany. Electronic address: roderich.suessmuth@tu-berlin.de.
Roderich D
RD
Süssmuth
Instituto de Biomedicina de Valencia, CSIC, Valencia, Spain. Electronic address: jcalvete@ibv.csic.es.
Juan J
JJ
Calvete
D000818:Animals; D054715:Cardiotoxins / Q000032:analysis; D000073178:Dendroaspis; D004546:Elapid Venoms / Q000032:analysis / Q000737:chemistry* / Q000633:toxicity; D008239:Lysine / Q000378:metabolism; D009498:Neurotoxins / Q000032:analysis; D010455:Peptides / Q000032:analysis; D011499:Protein Processing, Post-Translational; D020543:Proteome / Q000032:analysis*; D013045:Species Specificity; D053719:Tandem Mass Spectrometry
D054715:Cardiotoxins; D004546:Elapid Venoms; D009498:Neurotoxins; D010455:Peptides; D020543:Proteome; C020273:dendrotoxin; D008239:Lysine
Black mamba venom; Dendroaspis; Eastern green mamba venom; Elapidae; Snake venomics; Top-down proteomics