Eledoisin

Eledoisin is an undecapeptide of mollusk origin, belonging to the tachykinin family of neuropeptides.

Eledoisin

Names
IUPAC name (3S)-3-[[(2S)-6-amino-2-[[(2S)-3-hydroxy-2-[[(2S)-1-[(2S)-5-oxopyrrolidine-2-carbonyl]pyrrolidine-2-carbonyl]amino]propanoyl]amino]hexanoyl]amino]-4-[[(2S)-1-[[(2S)-1-[[(2S,3S)-1-[[2-[[(2S)-1-[[(2S)-1-amino-4-methylsulfanyl-1-oxobutan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]amino]-2-oxoethyl]amino]-3-methyl-1-oxopentan-2-yl]amino]-1-oxo-3-phenylpropan-2-yl]amino]-1-oxopropan-2-yl]amino]-4-oxobutanoic acid
Identifiers
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL373569
ChemSpider	6006
IUPHAR/BPS	2086
PubChem CID	10328936
UNII	OKY3285J18
CompTox Dashboard (EPA)	DTXSID1046926
InChI InChI=1/C54H85N13O15S/c1-7-30(4)44(53(81)57-27-42(70)60-36(24-29(2)3)49(77)61-33(45(56)73)20-23-83-6)66-50(78)37(25-32-14-9-8-10-15-32)63-46(74)31(5)58-48(76)38(26-43(71)72)64-47(75)34(16-11-12-21-55)62-51(79)39(28-68)65-52(80)40-17-13-22-67(40)54(82)35-18-19-41(69)59-35/h8-10,14-15,29-31,33-40,44,68H,7,11-13,16-28,55H2,1-6H3,(H2,56,73)(H,57,81)(H,58,76)(H,59,69)(H,60,70)(H,61,77)(H,62,79)(H,63,74)(H,64,75)(H,65,80)(H,66,78)(H,71,72) Key: AYLPVIWBPZMVSH-UHFFFAOYAZ
SMILES O=C(NC(C(=O)NC(C(=O)NC(C(=O)NC(C(=O)NC(C(=O)NC(C(=O)NCC(=O)NC(C(=O)NC(C(=O)N)CCSC)CC(C)C)C(C)CC)Cc1ccccc1)C)CC(=O)O)CCCCN)CO)C3N(C(=O)C2NC(=O)CC2)CCC3
Properties
Chemical formula	C54H85N13O15S
Molar mass	1188.40 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

It was first isolated from the posterior salivary glands of two mollusk species Eledone muschata and Eledone aldovandi, which belong to the octopod order of Cephalopoda. [1]

Other tachykinins from nonmammalian sources include kassinin and physalaemin. The mammalian tachykinins substance P, NKA, and NKB have similar effects as tachykinins of nonmammals and have been more widely studied and characterized. These peptides exhibit a wide and complex spectrum of pharmacological and physiological activities such as vasodilation, hypertension, and stimulation of extravascular smooth muscle.[2]

Eledoisin has the amino acid sequence pGlu-Pro-Ser-Lys-Asp-Ala-Phe-Ile-Gly-Leu-Met-NH2. Like all tachykinin peptides, Eledoisin shares the same consensus C-terminal sequence, that is, Phe-Xxx-Gly-Leu-Met-NH. The invariant "Phe7" residue is probably required for receptor binding. "Xxx" is either an aromatic (phenylalanine, tyrosine) or a branched aliphatic (valine, isoleucine) side chain and is thought to be important in receptor selectivity. This common region, often referred to as the "message domain," is believed to be responsible for activating the receptor. The divergent N-terminal region or the "address domain" varies in amino-acid sequence and length and is believed to play a role in determining the receptor subtype specificity. [3]

References

1. De Marco, A., and G. Gatti, "1H- and 13C-NMR spectra of eledoisin and intermediate oligopeptides." Int. J. Pep. Pro. Res. 7:437–444, 1975.
2. R. Christy Rani Grace, Indu R. Chandrashekar and Sudha M. Cowsik, "Solution Structure of the Tachykinin Peptide Eledoisin" Archived 2008-10-11 at the Wayback Machine, Biophysical Journal 84:655-664 (2003), retrieved 05 Dec 2007. This publication has excellent general information on the eledoisin molecule.
3. Schwyzer, R., "Membrane-assisted molecular mechanism of neurokinin receptor subtype selection." EMBO J. 6:2255–2259, 1987