SIIIB (P01615) Protein Card

General Information
Name SIIIB
Alternative name(s) S3b
Organism Conus striatus (Striated cone)
Organism region Indo-Pacific
Organism diet piscivorous
Protein Type Wild type
Notes The sequence present in the ncbi card and swiss prot cards are in fact corresponding to TIIIA (analogue sequence described in Schroeder et al. 2008 but different from SIIIB). The sequence presented here is extracted from Schroeder et al. 2008 and is consistent with SIIIA. Presumably interacts with site 1 in the Na channel pore, because SIIIB competes with TIIIA (Schroeder et al 2008), which in turn competes with saxitoxin (Lewis et al 2007).

Classification
Conopeptide class conotoxin
Gene superfamily M superfamily
Cysteine framework III
Pharmacological family mu conotoxin

Sequence
ZNCCNGGCSSKWCKGHARCC(nh2)
Modified residues
positionsymbolname
1ZPyroglutamic acid
21nh2C-term amidation
Sequence evidence protein level
Average Mass 2121.39
Monoisotopic Mass 2119.75
Isoelectric Point NA
Extinction Coefficient [280nm] NA

Activity

Ki: Voltage-Gated Sodium Channels

TargetOrganismKiCompetitorAgonistRef
Nav1.2R. norvegicus(Measured in rat brain preparation. )5.13 nM 125I-TIIIASchroeder,C.I. et al. (2008)
Nav1.4R. norvegicus(Measured in rat muscle preparation. )3.24 nm 125I-TIIIASchroeder,C.I. et al. (2008)

Percentage inhibition: Voltage-Gated Sodium Channels

TargetOrganism% inhibitionConcentrationRef
Nav1.2R. norvegicus933uMSchroeder,C.I. et al. (2008)
Nav1.7R. norvegicus103uMSchroeder,C.I. et al. (2008)

Synthetic variants
SIIIB[2-20]NCCNGGCSSKWCKGHARCC(nh2)

References
Schroeder,C.I., Ekberg,J., Nielsen,K.J., Adams,D., Loughnan,M.L., Thomas,L., Adams,D.J., Alewood,P.F. and Lewis,R.J. (2008) Neuronally mu-conotoxins from Conus striatus utilize an alpha-helical motif to target mammalian sodium channels. J. Biol. Chem. 283:21621-21628

Internal links
Nucleic acids
Structure

External links
UniProtKB/Swiss-Prot P0CE77
Ncbi P0CE77, P0C349

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