Calcicludine

Calcicludine is a protein toxin from the venom of the green mamba that inhibits high-voltage-activated calcium channel, especially L-type calcium channel[1][2].

O=C([C@@H](N)CC1=CNC2=CC=CC=C12)N[C@H](C(N3[C@H](C(N4[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N5[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(NCC(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N6[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(NC7)=O)CO)=O)CC8=CC=CC=C8)=O)CC(C)C)=O)CC9=CC=CC=C9)=O)CCC6)=O)CC(C)C)=O)CSSC[C@H](NC%10=O)C(N[C@H](C(N[C@H](C(N[C@H]%11CCCCN)=O)CCCCN)=O)CCCNC(N)=N)=O)=O)CCCCN)=O)CCCCN)=O)C)=O)[C@@H](C)O)=O)CC%12=CNC%13=CC=CC=C%12%13)=O)CCCCN)=O)CC%14=CC=CC=C%14)=O)CC%15=CC=C(O)C=C%15)=O)CC%16=CC=CC=C%16)=O)CO)=O)CO)=O)CC%17=CC=CC=C%17)=O)CCC(N)=O)=O)CCCCN)=O)CCCCN)=O)CSSC[C@H](NC7=O)C(NCC(NCC(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(NCC(N[C@H]%10CCC(O)=O)=O)=O)[C@H](CC)C)=O)[C@@H](C)O)=O)CCC(N)=O)=O)CC%18=CC=CC=C%18)=O)CCCNC(N)=N)=O)CC(N)=O)=O)C)=O)CC(N)=O)=O)=O)=O)=O)CO)=O)=O)[C@H](CC)C)=O)CCCNC(N)=N)=O)C(C)C)=O)CCC5)=O)CCC(O)=O)=O)CCCCN)=O)CSSC[C@H](NC%11=O)C(N[C@H](C(NCC(N[C@H](C(O)=O)CCCCN)=O)=O)CC(C)C)=O)=O)CC%19=CC=C(O)C=C%19)=O)CC%20=CNC%21=CC=CC=C%20%21)=O)CCC4)=O)CCC3)=O)CCC(N)=O

[1]H Schweitz, et al. Calcicludine, a venom peptide of the Kunitz-type protease inhibitor family, is a potent blocker of high-threshold Ca2+ channels with a high affinity for L-type channels in cerebellar granule neurons. Proc Natl Acad Sci U S A. 1994 Feb 1;91(3):878-82.|[2]S C Stotz, et al. Block of Voltage-dependent Calcium Channel by the Green Mamba Toxin Calcicludine. J Membr Biol. 2000 Mar 15;174(2):157-65.