Peptide name : Cecropin A

Source/Organism : Giant silk moth, cecropia moth

Linear/Cyclic : Not found

Chirality : Not found

Peptide length: 37

C-terminal modification: Not found

N-terminal modification : Free

Non-natural peptide information: None

Assay type : Not specified

Assay time : Not found

Activity : Not found

Cell line : Not found

Cancer type : Not found

Other activity : Anti-bacterial activity

Amino acid composition bar chart :

Molecular mass : 4004.7658 Dalton

Aliphatic index : 1.081

Instability index : 16.5243

Hydrophobicity (GRAVY) : -0.073

Isoelectric point : 10.391

Charge (pH 7) : 5.757

Aromaticity : 0.054

Molar extinction coefficient (cysteine, cystine): (5500, 5500)

Hydrophobic/hydrophilic ratio : 1.46666666

hydrophobic moment : 0.652

Missing amino acid : C,H,M,S,Y

Most occurring amino acid : K

Most occurring amino acid frequency : 7

Least occurring amino acid : W

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.3, 0.1, 0.3)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)CNC(=O)[C@H](CC(=O)O)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@@H](NC(=O)[C@H](CC(N)=O)NC(=O)[C@H](CCC(N)=O)NC(=O)CNC(=O)[C@@H](NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@@H](NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCCCN)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCCCN)NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@@H](N)CCCCN)[C@@H](C)CC)C(C)C)[C@@H](C)CC)C(=O)N[C@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](C)C(=O)NCC(=O)N1CCC[C@H]1C(=O)N[C@@H](C)C(=O)N[C@H](C(=O)N[C@@H](C)C(=O)N[C@H](C(=O)N[C@H](C(=O)NCC(=O)N[C@@H](CCC(N)=O)C(=O)N[C@@H](C)C(=O)N[C@H](C(=O)N[C@@H](CCC(N)=O)C(=O)N[C@H](C(=O)N[C@@H](C)C(=O)N[C@@H](CCCCN)C(=O)O)[C@@H](C)CC)[C@@H](C)O)C(C)C)C(C)C)C(C)C)[C@@H](C)CC

1 : Steiner H, et al. Sequence and specificity of two antibacterial proteins involved in insect immunity. Nature. 1981; 292:246-8. doi: 10.1038/292246a0

Paper title : Sequence and specificity of two antibacterial proteins involved in insect immunity.

Doi : https://doi.org/10.1038/292246a0

Abstract : Immune responses have been described for many different insect species. However, it is generally acknowledged that immune systems must therefore differ from those of vertebrates. An effective humoral immune response has been found in pupae of the cecropia moth, Hyalophora cecropia. The expression of this multicomponent system requires de novo synthesis of RNA and proteins and its broad antibacterial activity is due to at least three independent mechanisms, the most well known of which is the insect lysozyme. However, this enzyme is bactericidal for only a limited number of Gram-positive bacteria. WE recently purified and characterized P9A and P9B, which are two small, basic proteins with potent antibacterial activity against Escherichia coli and several other Gram-negative bacteria. We believe that P9A and P9B plays an important part in the humoral immune responses described previously and that the P9 proteins represent a new class of antibacterial agents for which we propose the name cecropins. We describe here the primary structures of cecropins A and B. We also show that cecropin A is specific for bacteria in contrast to melittin, the main lytic component in bee venom which lyses both bacteria and eukaryotic cells.