KIDGYPVDYWNCKRICWYNNKYCNDLCKGLKADSGYCWGWTLSCYCQGLPDNARIKRSGRCRA
Calciseptine RI
CYIHKASLPRATKT
CVENT
CYKMFIRTQREYISERG
CG
CPTAMWPYQTE
CCKGDR
CNK
P22947Calcicludine WQPPWY
CKEPVRIGS
CKKQFSSFYFKWTAKK
CLPFLFSG
CGGNANRFQTIGE
CRKK
CLGK
P81658 CVID _______
CKSKGAK
CSKLMYD
CCSGS
CSGTVGR
C P58920GVIA _______
CKS PGSS
CSPTSYN
CCRS
CNPYTKR
CY
P01522MVIIA_______
CKGKGAK
CSRLMYD
CCTGS
CRSGK
C P05484MVIIC ______
CKGKGAP
CRKTMYD
CCSGS
CGRRGK
C P37300SVIB ________
CKLKGQS
CRKT SYD
CCSGS
CGRSGK
C P28881 Tx3-1 _____AE
CAAVYER
CGKGYKR
CCEERP
CK
CNIVMDN
CT
CKKFISE
O76200Tx3-2 _____ A
CAGLYKK
CGKGASP
CCEDRP
CK
CDLAMGN
CI
CK
O76201Tx3-3 _____G
CANAYKS
CNGPHT
CCWGYNGYKKA
CI
CSGXNWK
P81789Tx3-4 _____S
CINVGDF
CDGKKDD
CQ
CCRDNAF
CS
CSVIFGYKTN
CR
P81790__________CEVGTTATSYGI
CMAKHK
CGRQTT
CTKP
CLSKR
CKKNH
Tx3-6 _____A
CIPRGEI
CTDD
CE
CCG
CDNQ
CY
CPPGSSLGIFK
CS
CAHANKYF
CNRKKEK
CKKA
P81792PRTx3-7 ___A
CAGLYKK
CGKGVNT
CCENRP
CK
CDLAMGN
CI
CKKKFVEFFGG
P83911 ω−Conotoxins CVID, GVIA, MVIIA, MVIIC and SVIB.
Tx3-3 (also named ω-PnTx3-3) revealed that its effect on blocking glutamate and acetylcholine release is additive to that of ω-agatoxin IVA. In brain cortical synaptosomes, Tx3-3 blocks P/Q-type calcium channels with an IC50 of 0.9 nM
electrophysiology experiments show that Tx3-3 also blocks P/Q- and R-type currents in cerebellar granule cells with an IC50 of 12 nM
Another sub-fraction of PhTx3 called Tx3-4 or ω-Phonetoxin IIA also blocks P/Q-type calcium channels in brain synaptosomes with an IC50 of 7.9 nM
Tx3-4 inhibits calcium channels coupled to KCl-induced exocytosis of synaptic vesicles with an IC50 of 1.1 nM and that the P/Q-type calcium channels are the main target of the toxin
is not a very selective toxin. It is a 74 amino acid peptide toxin with a sequence containing 12 cysteines isolated from the venom of Filista hibernalis
IC50s of 50 nM and 150 nM were recorded for ProTx-I and II, respectively. To summarize, it seems that the toxin-channel interaction surface should be similar in these sodium and calcium channel subtypes.
Filistatoxin peptidic sequence.
ProTx-I__________ECRYWLGGCSAGQTCCKHLVCSRRHGWCVWDGTFS
ProTx-II___________YCQKWMWTCDSERKCCEGMVCRLWCKKKLW
ω-FLTX-Kh1a _____AE
CLMIGDTS
CVPRLGRR
CCYGAW
CY
CDQQLS
CRRVGRKRE
CGWVEVN
CK
CGWSWSQRIDDWRADYS
CK
CPEDQ
P60979 Two peptides, ProTx-I and ProTx-II, from the venom of the green velvet tarantula Thrixopelma pruniens, have been isolated and characterized
[Peptide Neurotoxins that Affect Voltage-Gated Calcium Channels: A Close-Up on ω-Agatoxins]