| | Identification | Back Directory |  | [Name] 
 APAMIN
 |  | [CAS] 
 24345-16-2
 |  | [Synonyms] 
 APAMIN
 apamine
 APAMIN, BEE VENOM
 Apamin, ≥97% (HPLC)
 APAMIN FROM BEE VENOM
 CNCKAPETALCARRCQQH-NH2
 APAMIN FROM HONEY BEE VENOM
 Apamin (trifluoroacetate salt)
 M.W. 2027.34    C79H131N31O24S4
 APAMIN (HONEY BEE, APIS MELIFERA)
 APAMIN (HONEYBEE, APIS MELLIFERA)
 Apamin, Bee Venom - CAS 24345-16-2 - Calbiochem
 CNCKAPETALCARRCQQH-NH2 (DISULFIDE BRIDGE: 1-11,3-15)
 CYS-ASN-CYS-LYS-ALA-PRO-GLU-THR-ALA-LEU-CYS-ALA-ARG-CYS-GLN-GLN-HIS-NH2
 CYS-ASN-CYS-LYS-ALA-PRO-GLU-THR-ALA-LEU-CYS-ALA-ARG-ARG-CYS-GLN-GLN-HIS-NH2
 H-CYS-ASN-CYS-LYS-ALA-PRO-GLU-THR-ALA-LEU-CYS-ALA-ARG-ARG-CYS-GLN-GLN-HIS-NH2
 H-+CYS-ASN-++CYS-LYS-ALA-PRO-GLU-THR-ALA-LEU-+CYS-ALA-ARG-ARG-++CYS-GLN-GLN- HIS-NH2
 [CYS-ASN-(CYS-LYS-ALA-PRO-GLU-THR-ALA-LEU-CYS]CYCL-ALA-ARG-ARG-CYS)CYCL-GLN-GLN-HIS-NH2
 H-Cys-Asn-Cys-Lys-Ala-Pro-Glu-Thr-Ala-Leu-Cys-Ala-Arg-Arg-Cys-Gln-Gln-His-NH2 (Cys1-Cys11, Cys3-Cys15)
 H-CYS-ASN-CYS-LYS-ALA-PRO-GLU-THR-ALA-LEU-CYS-ALA-ARG-ARG-CYS-GLN-GLN-HIS-NH2 (DISULFIDE BRIDGE: 1-11, 3-15)
 L-Cys-L-Asn-L-Cys-L-Lys-L-Ala-L-Pro-L-Glu-L-Thr-L-Ala-L-Leu-L-Cys-L-Ala-L-Arg-L-Arg-L-Cys-L-Gln-L-Gln-L-His-NH2
 CYS-ASN-CYS-LYS-ALA-PRO-GLU-THR-ALA-LEU-CYS-ALA-ARG- ARG-CYS-GLN-GLN-HIS-NH2(DISULFIDE BRIDGE:CYS1-CYS11, CYS3-CYS15)
 L-Cysteinyl-L-asparaginyl-L-cysteinyl-L-lysyl-L-alanyl-L-prolyl-L-alpha-glutamyl-L-threonyl-L-alanyl-L-leucyl-L-cysteinyl-L-alanyl-L-arginyl-L-arginyl-L-cysteinyl-L-glutaminyl-L-glutaminyl-L-histidinamide cyclic (1-11) (3-15)-bis(disulfide) = Cys-Asn-Cys-Lys-Ala-Pro-Glu-Thr-Ala-leu-Cyc-Ala-Arg-Arg-Cys-Gln-Gln-His-NH2
 |  | [EINECS(EC#)] 
 246-182-7
 |  | [Molecular Formula] 
 C79H131N31O24S4
 |  | [MDL Number] 
 MFCD00167944
 |  | [MOL File] 
 24345-16-2.mol
 |  | [Molecular Weight] 
 2027.34
 | 
 | Chemical Properties | Back Directory |  | [Boiling point ] 
 847.17°C (rough estimate)
 |  | [density ] 
 1.63
 |  | [refractive index ] 
 1.5530 (estimate)
 |  | [storage temp. ] 
 -20°C
 |  | [solubility ] 
 0.05 M acetic acid: 5 mg/mL, clear, colorless to faintly yellow
 
 |  | [form ] 
 White solid with dark tan cast
 |  | [color ] 
 White to off-white
 |  | [biological source] 
 synthetic
 |  | [Water Solubility ] 
 Soluble to 1 mg/ml in water
 |  | [Merck ] 
 13,732
 |  | [Sequence] 
 Cys-Asn-Cys-Lys-Ala-Pro-Glu-Thr-Ala-Leu-Cys-Ala-Arg-Arg-Cys-Gln-Gln-His-NH2 (Disulfide bridge: Cys1-Cys11;Cys3-Cys15)
 | 
 | Safety Data | Back Directory |  | [Safety Statements ] 
 22-24/25
 |  | [RIDADR ] 
 2811
 |  | [WGK Germany ] 
 3
 
 |  | [RTECS ] 
 CD6899900
 
 |  | [F ] 
 3-10
 |  | [HazardClass ] 
 6.1(b)
 |  | [PackingGroup ] 
 III
 |  | [Toxicity] 
 LD50 i.v. in mice:  4 mg/kg (Habermann, Reiz); LD50 intracerebroventricularly in mice:  12 ng/animal (Labbé-Jullié)
 | 
 | Hazard Information | Back Directory |  | [Chemical Properties] 
 Small, highly potent, highly basic polypeptide.
 |  | [Uses] 
 Apamin has been used:
 
 As a selective inhibitor of small conductance (SKCa) channels in HEK cells.To inhibit endothelium-derived relaxing factor (EDHF) mediated responses.To block small-conductance Ca2-activated K current (ISK) in electrophysiological studies in hyperstriatum ventrale, pars caudalis (HVc) neurons.
 
 |  | [Definition] 
 Occurs in the venom of the honey bee, Apis mellifera; molecular weight of 2027.38.
 |  | [General Description] 
 Apamin is a bee venom component and is strongly basic in nature. It has 18 amino acid residues and two disulphide bonds.
 |  | [Hazard] 
 Central nervous system poison able to cross the blood–brain barrier; neurotoxic; poison.
 |  | [Biochem/physiol Actions] 
 Apamin is a neurotoxin which can pass the blood-brain barrier. In human, it might cause peripheral nerve dysfunction, mainly seen after bee stings.
 |  | [Safety Profile] 
 Poison by intravenous, parenteral,intracerebral, and intraperitoneal routes. When heated todecomposition it emits toxic fumes of SOx and NOx.
 |  | [Enzyme inhibitor] 
 This bee venom octadecapeptide toxin (FW = 2027.34 g/mol; CAS 24345- 16-2; NCBI Reference Sequence: NP_001011612.1) potently blocks the  small-conductance Ca 2+ -activated potassium ion (or SK) channels hSK1 as  well as rSK2, with IC50  values of 3.3 nM and 83 pM. It shows greater  effectiveness at the SK2 channel (IC50 = 0.06-0.4 nM) than SK1 (IC50 = 1- 12 nM). SK3 (IC50 = 1-13 nM), and SK4 (IC50 = 1 μM) channels, and  is  active against channels within neurons, vascular endothelium, bladder  smooth muscle, and certain cancers. Apamin does not inhibit human  cardiac Na +   current, L-type Ca 2+   current or other major K+   currents.  Structurally, apamin forms a stable structure, consisting of a C-terminal a- helix and two reverse turns, that is stabilized by two disulfide bonds  connecting Cys-1 to Cys-11 and Cys-3 to Cys-15. A minor constituent of  venom of the bee (Apis mellifera), apamin amounts to only 2-3% (w/w) of  its dry venom.  The smallest known neurotoxic polypeptide, apamin is  derived by proteolytic processing of the 48-residue pre-pro-protein.  The precursors of the bee venom constituents apamin and MCD peptide are  encoded by two genes in tandem which share the same 3'-exon.
 |  | [storage] 
 -20°C (desiccate)
 | 
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