Sarafotoxin

Atractaspis engaddensis
Sarafotoxin a (SRTXa, S6a)
Identifiers
  • N-({(1R,4S,7S,10S,13S,16S,19S,22S,25R,28S,31R,36R,39S,42S,45S)-31-Amino-7,22-bis(4-aminobutyl)-42-(2-amino-2-oxoethyl)-39-benzyl-4-(2-carboxyethyl)-10,19-bis(carboxymethyl)-13-(1-hydroxyethyl)-28-(hyd roxymethyl)-45-isobutyl-16-[2-(methylsulfanyl)ethyl]-3,6,9,12,15,18,21,24,27,30,38,41,44,47-tetradecaoxo-33,34,49,50-tetrathia-2,5,8,11,14,17,20,23,26,29,37,40,43,46-tetradecaazabicyclo[23.22.4]henpen tacont-36-yl}carbonyl)-L-histidyl-L-glutamin
CAS Number
PubChem CID
ChemSpider
Chemical and physical data
FormulaC105H156N28O34S5
Molar mass2514.86 g·mol−1
3D model (JSmol)
  • CCC(C)C(C(=O)NC(CC1=CNC2=CC=CC=C21)C(=O)O)NC(=O)C(C(C)C)NC(=O)C(CC(=O)O)NC(=O)C(CCC(=O)N)NC(=O)C(CC3=CNC=N3)NC(=O)C4CSSCC(C(=O)NC(C(=O)NC5CSSCC(C(=O)NC(C(=O)NC(C(=O)NC(C(=O)N4)CC6=CC=CC=C6)CC(=O)N)CC(C)C)NC(=O)C(NC(=O)C(NC(=O)C(NC(=O)C(NC(=O)C(NC(=O)C(NC(=O)C(NC5=O)CCCCN)CC(=O)O)CCSC)C(C)O)CC(=O)O)CCCCN)CCC(=O)O)CO)N

Sarafotoxins (SRTXs) are a group of toxins present in the venom of Atractaspis engaddensis, and in clinical trials cause similar symptoms to patients diagnosed with acute giardiasis.[1] Their etymology is from the name of the snake "שרף עין גדי" in Hebrew, pronounced "Saraf Ein Gedi" (meaning serpent of Ein Gedi).[2] Together with endothelins (ETs), they form a homogenous family of strong vasoconstrictor isopeptides. Among them, a few slightly different substances can be named as SRTX-a, SRTX-b, SRTX-c, which were initially derived from A. engaddensis. Each one contains twenty-one amino acid residues that spontaneously fold into a defined tertiary structure, with two interchain-cysteine linkages (disulfide bonds) and a long hydrophobic tail.[3] There are also other compounds, however, they are mostly derivations of previously mentioned ones. The main differences in the family of endothelin and sarafotoxins appear at N-terminal of peptides, as C-terminal in all of them is almost the same.[4]

Sarafotoxin b (SRTXb, S6b)
Identifiers
  • N-({(1R,4S,7S,10S,13S,16S,19S,22S,25R,28S,31R,36R,39S,42S,45S)-31-Amino-7,22-bis(4-aminobutyl)-39-benzyl-4-(2-carboxyethyl)-10,19-bis(carboxymethyl)-42-(4-hydroxybenzyl)-13-(1-hydroxyethyl)-28-(hydrox ymethyl)-45-isobutyl-16-[2-(methylsulfanyl)ethyl]-3,6,9,12,15,18,21,24,27,30,38,41,44,47-tetradecaoxo-33,34,49,50-tetrathia-2,5,8,11,14,17,20,23,26,29,37,40,43,46-tetradecaazabicyclo[23.22.4]henpentac ont-36-yl}carbonyl)-L-histidyl-L-glutamin
CAS Number
PubChem CID
ChemSpider
Chemical and physical data
FormulaC110H159N27O34S5
Molar mass2563.94 g·mol−1
3D model (JSmol)
  • CCC(C)C(C(=O)NC(CC1=CNC2=CC=CC=C21)C(=O)O)NC(=O)C(C(C)C)NC(=O)C(CC(=O)O)NC(=O)C(CCC(=O)N)NC(=O)C(CC3=CN=CN3)NC(=O)C4CSSCC(C(=O)NC(C(=O)NC5CSSCC(C(=O)NC(C(=O)NC(C(=O)NC(C(=O)N4)CC6=CC=CC=C6)CC7=CC=C(C=C7)O)CC(C)C)NC(=O)C(NC(=O)C(NC(=O)C(NC(=O)C(NC(=O)C(NC(=O)C(NC(=O)C(NC5=O)CCCCN)CC(=O)O)CCSC)C(C)O)CC(=O)O)CCCCN)CCC(=O)O)CO)N
Sarafotoxin c (SRTXc, S6c)
Identifiers
  • 3-[2-(2-{[31-amino-39-benzyl-22,42-bis(carbamoylmethyl)-4,7-bis(2-carboxyethyl)-10,19-bis(carboxymethyl)-13,28-bis(1-hydroxyethyl)-45-(2-methylpropyl)-16-[2-(methylsulfanyl)ethyl]-3,6,9,12,15,18,21,24,27,30,38,41,44,47-tetradecaoxo-33,34,49,50-tetrathia-2,5,8,11,14,17,20,23,26,29,37,40,43,46-tetradecaazabicyclo[23.22.4]henpentacontan-36-yl]formamido}-3-(1H-imidazol-5-yl)propanamido)-4-carbamoylbutanamido]-3-({1-[(1-{[1-carboxy-2-(1H-indol-3-yl)ethyl]carbamoyl}-2-methylbutyl)carbamoyl]-2-methylpropyl}carbamoyl)propanoic acid
CAS Number
ChemSpider
Chemical and physical data
FormulaC103H147N27O37S5
Molar mass2515.76 g·mol−1
3D model (JSmol)
  • CCCCC1C(=O)NC(C(=O)NC(C(=O)NC(C(=O)NC(C(=O)NC2CSSCC(C(=O)NC(C(=O)NC(C(=O)N1)CC(=O)O)CC(=O)N)NC(=O)C(NC(=O)C(CSSCC(NC(=O)C(NC(=O)C(NC(=O)C(NC2=O)CC(C)C)CC(=O)N)CC3=CC=CC=C3)C(=O)NC(CC4=CNC=N4)C(=O)NC(CCC(=O)N)C(=O)NC(CC(=O)O)C(=O)NC(C(C)C)C(=O)NC(C(C)CC)C(=O)NC(CC5=CNC6=CC=CC=C65)C(=O)O)N)C(C)O)CCC(=O)O)CCC(=O)O)CC(=O)O)C(C)O
Safarotoxin (and endothelin) schematic pathway representation.
  1. ^ Solarczyk P, Majewska A (2015). "Implications of Giardia taxonomic controversies and genetic diversity". Problemy Higieny I Epidemiologii. 96 (3): 540–546.
  2. ^ Takasaki C, Tamiya N, Bdolah A, Wollberg Z, Kochva E (1988-06-01). "Sarafotoxins S6: several isotoxins from Atractaspis engaddensis (burrowing asp) venom that affect the heart". Toxicon. 26 (6): 543–8. doi:10.1016/0041-0101(88)90234-6. PMID 3176048.
  3. ^ Nayler WG, Gu XH, Casley DJ (May 1989). "Sarafotoxin S6c is a relatively weak displacer of specifically bound 125I-endothelin". Biochemical and Biophysical Research Communications. 161 (1): 89–94. doi:10.1016/0006-291x(89)91564-7. PMID 2543414.
  4. ^ Kloog Y, Sokolovsky M (June 1989). "Similarities in mode and sites of action of sarafotoxins and endothelins". Trends in Pharmacological Sciences. 10 (6): 212–4. doi:10.1016/0165-6147(89)90261-7. PMID 2549664.