EI (P00050) Protein Card

General Information
Name EI
Organism Conus ermineus (Atlantic fish-hunting cone)
Organism region Western Atlantic and Caribbean,Eastern Atlantic and Mediterranean
Organism diet piscivorous
Protein Type Wild type
Protein precursor EI precursor (3000)

Classification
Conopeptide class conotoxin
Gene superfamily A superfamily
Cysteine framework I
Pharmacological family alpha conotoxin

Sequence
RDOCCYHPTCNMSNPQIC(nh2)
Modified residues
positionsymbolname
3O4-Hydroxyproline
19nh2C-term amidation
Sequence evidence protein level
Average Mass 2093.36
Monoisotopic Mass 2091.78
Isoelectric Point 7.98
Extinction Coefficient [280nm] 1490.00

Activity

IC50: Nicotinic acetylcholine receptors

TargetOrganismIC50nhillAgonistRef
α1β1δεM. musculus65.9 nM[58.5-74.2]1.3ACh(10 uM)Ning,J. et al. (2019)
α1β1γδUnknown0.37nM+/-0.230.46 50uM nicotineLópez-Vera,E. et al. (2007)
α3β2R. norvegicus7297 nM[3748-14200]0.8ACh(100 uM)Ning,J. et al. (2019)
α3β4R. norvegicus6444 nM[5443-7628]1.4ACh(100 uM)Ning,J. et al. (2019)

Percentage inhibition: Nicotinic acetylcholine receptors

TargetOrganism% inhibitionConcentrationAgonistRef
α1β1γδUnknown4010uM 50uM nicotineLópez-Vera,E. et al. (2007)
α3β4Unknown010uM50uM nicotineLópez-Vera,E. et al. (2007)
α4β2Unknown5510uM50uM nicotineLópez-Vera,E. et al. (2007)

Synthetic variants
EI[D2A]RAOCCYHPTCNMSNPQIC(nh2)
EI[H7A]RDOCCYAPTCNMSNPQIC(nh2)
EI[I17A]RDOCCYHPTCNMSNPQAC(nh2)
EI[M12A]RDOCCYHPTCNASNPQIC(nh2)
EI[N11A]RDOCCYHPTCAMSNPQIC(nh2)
EI[N14A]RDOCCYHPTCNMSAPQIC(nh2)
EI[O3A]RDACCYHPTCNMSNPQIC(nh2)
EI[P15A]RDOCCYHPTCNMSNAQIC(nh2)
EI[P8A]RDOCCYHATCNMSNPQIC(nh2)
EI[Q16A]RDOCCYHPTCNMSNPAIC(nh2)
EI[R1A]ADOCCYHPTCNMSNPQIC(nh2)
EI[S13A]RDOCCYHPTCNMANPQIC(nh2)
EI[T9A]RDOCCYHPACNMSNPQIC(nh2)
EI[Y6A]RDOCCAHPTCNMSNPQIC(nh2)
EI[del1-2]OCCYHPTCNMSNPQIC(nh2)
EI[del1-3]CCYHPTCNMSNPQIC(nh2)
EI[del1]DOCCYHPTCNMSNPQIC(nh2)

References
Martinez,J.S., Olivera,B.M., Gray,W.R., Craig,A.G., Groebe,D.R., Abramson,S.N. and McIntosh,J.M. (1995) alpha-Conotoxin EI, a new nicotinic acetylcholine receptor antagonist with novel selectivity Biochemistry 34:14519-14526
Park,K.H., Suk,J.E., Jacobsen,R., Gray,W.R., McIntosh,J.M. and Han,K.H. (2001) Solution conformation of alpha-conotoxin EI, a neuromuscular toxin specific for the alpha 1/delta subunit interface of torpedo nicotinic acetylcholine receptor J. Biol. Chem. 276:49028-49033
López-Vera,E., Aguilar,M.B., Schiavon,E., Marinzi,C., Ortiz,E., Restano Cassulini,R., Batista,C.V., Possani,L.D., Heimer de la Cotera,E.P., Peri,F., Becerril,B. and Wanke,E. (2007) Novel alpha-conotoxins from Conus spurius and the alpha-conotoxin EI share high-affinity potentiation and low-affinity inhibition of nicotinic acetylcholine receptors. FEBS J. 274:3972-3985
Ning,J., Ren,J., Xiong,Y., Wu,Y., Zhangsun,M., Zhangsun,D., Zhu,X. and Luo,S. (2019) Identification of Crucial Residues in α-Conotoxin EI Inhibiting Muscle Nicotinic Acetylcholine Receptor Toxins (Basel) 11:603

Internal links
Protein Precursor EI precursor (3000)
Nucleic acids
Structure NMR STRUCTUE OF ALPHA-CONOTOXIN EI

External links
UniProtKB/Swiss-Prot P50982
Ncbi 1K64_A, P50982

Tools