General Information

    • DRAMP ID

    • DRAMP00878

    • Peptide Name

    • Circulin-B (CIRB; Plant defensin)

    • Source

    • Chassalia parviflora

    • Family

    • Belongs to the cyclotide family

    • Gene

    • Not found

    • Sequence

    • GVIPCGESCVFIPCISTLLGCSCKNKVCYRN

    • Sequence Length

    • 31

    • Protein Existence

    • Protein level

Activity Information

    • Biological Activity

    • Antimicrobial, Antibacterial, Anti-Gram+, Anti-Gram-, Antiviral, Antifungal

    • Target Organism

      • [Ref.10430870]Gram-positive bacterium: (L-salt): Staphylococcus aureus (MIC=13.5 µM).
      • Gram-negative bacteria: (L-salt, H-salt) (MIC µM): Escherichia coli (0.41, >500), Pseudomonas aeruginosa (25.5, 48), Proteus vulgaris (6.8, >500), Klebsiella oxytoca (8.2, 15.6).
      • Fungi (H-salt): Candida kefyr (MIC=29 µM).
      • NOTE: L-salt = Medium with 10 mM phosphate buffer; H-salt = L-salt supplemented with 100 mM NaCl.
      • [Ref.18008336]Virus:HIV:inhibition the cytopathic effects of HIV-1 infection in cultured human T-lymphoblast (CEM-SS) cells(EC50=40-260 nM).

    • Hemolytic Activity

      • [Ref.10430870] EC50 = 550 μM against blood type A human erythrocytes.

    • Cytotoxicity

      • [Ref.10430870] It caused 50% cell growth inhibition of mouse fibroblasts at 820 μM.
      • [Ref.18008336]CEM-SS cells:IC50=500 nM.

    • Binding Target

    • Not found

Structure Information

    • Linear/Cyclic

    • Cyclic

    • N-terminal Modification

    • Cyclization (N termini to C termini)

    • C-terminal Modification

    • Cyclization (C termini to N termini)

    • Nonterminal Modifications and Unusual Amino Acids

    • [Ref.8920961] There are three disulfide bonds between Cys5 and Cys19, Cys9 and Cys21, Cys14 and Cys27.

    • Stereochemistry

    • L

    • Structure

    • Beta strand (5 strands; 10 residues)

    • Structure Description

    • Cyclotides are mini-proteins derived from plants that have the characteristic features of a head-to-tail cyclised peptide backbone and a knotted arrangement of their three disulfide bonds.

    • Helical Wheel Diagram

    • DRAMP00878 helical wheel diagram

    • PDB ID

    • 2ERI resolved by NMR.

    • Predicted Structure

    • There is no predicted structure for DRAMP00878.

Physicochemical Information

    • Formula

    • C141H232N38O41S6

    • Absent Amino Acids

    • ADHMQW

    • Common Amino Acids

    • C

    • Mass

    • 3307.98

    • PI

    • 8.33

    • Basic Residues

    • 3

    • Acidic Residues

    • 1

    • Hydrophobic Residues

    • 9

    • Net Charge

    • +2

    • Boman Index

    • -8.82

    • Hydrophobicity

    • 0.642

    • Aliphatic Index

    • 90.97

    • Half Life

      • Mammalian:30 hour
      • Yeast:>20 hour
      • E.coli:>10 hour

    • Extinction Coefficient Cystines

    • 1865

    • Absorbance 280nm

    • 62.17

    • Polar Residues

    • 16

DRAMP00878

DRAMP00878 chydropathy plot

Comments Information

    • Function

    • Probably participates in a plant defense mechanism. Has antibiotic activity. Inhibits the cytopathic effects and replication of the human immunodeficiency virus. Active against both Gram-positive and Gram-negative bacteria.

    • PTM

    • This is a cyclic peptide which contains three disulfide bonds 5-21; 9-23; 14-28.

Literature Information

  • ·Literature 1

    • Title

    • An unusual structural motif of antimicrobial peptides containing end-to-end macrocycle and cystine-knot disulfides.

    • 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

    • Cyclotides as natural anti-HIV agents.

    • Reference

    • Biopolymers. 2008;90(1):51-60.

    • Author

    • Ireland DC, Wang CK, Wilson JA, Gustafson KR, Craik DJ.
  • ·Literature 3

    • Title

    • Analysis of the disulfide linkage pattern in circulin A and B, HIV-inhibitory macrocyclic peptides

    • Reference

    • Biochem Biophys Res Commun. 1996 Nov 12;228(2):632-8. doi: 10.1006/bbrc.1996.1708.

    • Author

    • R Derua 1, K R Gustafson, L K Pannell