General Information
Activity Information
-
Biological Activity
- Antibacterial, Antifungal, Antiviral, Anti-Gram+, Anti-Gram-, Antimicrobial
-
Target Organism
-
- Gram-positive bacterium: Staphylococcus aureus (MIC=0.19 µM).
- Gram-negative bacterium: Proteus vulgaris (MIC=54.6 µM).
- Fungi: Candida kefyr (MIC=18.6 µM) and Candida tropicalis (MIC=19.4 µM).
- NOTE: Medium with 10 mM phosphate buffer.
-
Hemolytic Activity
-
- [Ref.10430870] EC50 = 1020 μM against blood type A human erythrocytes (1.8 × 10^8 cells/ml). Note: EC50 is the peptide concentrations causing 50% hemolysis.
-
Cytotoxicity
- No cytotoxicity information found in the reference(s) presented
-
Binding Target
- Not found
Structure Information
-
Linear/Cyclic
- Cyclic
-
N-terminal Modification
- No specific N-terminal
-
C-terminal Modification
- No specific C-terminal
-
Other Modifications and Unusual Amino Acids
- Disulfide bonds between Cys1 and Cys17; Cys5 and Cys19; Cys10 and Cys24.
-
Stereochemistry
- L
-
Structure
- Alpha helix (1 helices; 4 residues)
-
Structure Description
- The molecule is stabilised by three disulfide bonds, two of which form an embedded loop completed by the backbone fragments connecting the cysteine residues. A third disulfide bond threads through the centre of this loop to form a "cystine-knot" motif. This motif is present in a range of other biologically active proteins, including omega-contoxin GVIA and Cucurbita maxima trypsin inhibitor.
-
PDB ID
- 1BH4 resolved by NMR.
-
-
-
1BH4-> 
-
Physicochemical Information
-
Formula
- C134H216N38O39S6
Absent Amino Acids
- DFHMQT
Common Amino Acids
- C
Mass
- 3693.25
PI
- 8.11
Basic Residues
- 3
Acidic Residues
- 1
Hydrophobic Residues
- 9
-
Boman Index
- -12.24
Hydrophobicity
- 0.417
Aliphatic Index
- 78
Half Life
-
- Mammalian:30 hour
- Yeast:>20 hour
- E.coli:>10 hour
Extinction Coefficient Cystines
- 7365
Absorbance 280nm
- 253.97
Polar Residues
- 15
DRAMP00877

Comments Information
Function
- Probably participates in a plant defense mechanism. Has antibiotic activity. Inhibits the cytopathic effects and replication of the human immunodeficiency virus. Relatively ineffective against Gram-negative bacteria such as E. coli and P. aeruginosa.
PTM
- This is a cyclic peptide which contains three disulfide bonds 1-17; 5-19; 10-24.
Literature Information
- ·Literature 1
-
Title
- An unusual structural motif of antimicrobial peptides containing end-to-end macrocycle and cystine-knot disulfides.
-
Pubmed ID
- 10430870
-
Reference
- Proc Natl Acad Sci U S A. 1999 Aug 3;96(16):8913-8918.
-
Author
- Tam JP, Lu YA, Yang JL, Chiu KW.
- ·Literature 2
-
Title
- Solution structure by NMR of circulin A: a macrocyclic knotted peptide having anti-HIV activity.
-
Pubmed ID
- 9878410
-
Reference
- J. Mol. Biol. 1999; 285:333-345.
-
Author
- Daly NL, Koltay A, Gustafson KR, Boyd MR, Casas-Finet JR, Craik DJ.