Peptide name : Tachyplesin I (Tac; TP1; Horseshoe Crab, arachnids, Chelicerata, arthropods, invertebrates, animals)

Source/Organism : Japanese horseshoe crab

Linear/Cyclic : Cyclic

Chirality : L

Peptide length: 17

C-terminal modification: Cyclic

N-terminal modification : Amidation (Arg17)

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-microbial activity

Amino acid composition bar chart :

Molecular mass : 2268.7577 Dalton

Aliphatic index : 0.4

Instability index : 13.2235

Hydrophobicity (GRAVY) : -0.517

Isoelectric point : 9.931

Charge (pH 7) : 5.7175

Aromaticity : 0.235

Molar extinction coefficient (cysteine, cystine): (8480, 8730)

Hydrophobic/hydrophilic ratio : 1.125

hydrophobic moment : -0.291

Missing amino acid : H,Q,T,P,M,E,S,D,L,N,A

Most occurring amino acid : R

Most occurring amino acid frequency : 5

Least occurring amino acid : K

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.0, 0.0, 0.3)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)CNC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](Cc1ccc(O)cc1)NC(=O)[C@H](CS)NC(=O)[C@@H](NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](CS)NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@@H](N)CCCCN)C(C)C)C(=O)N[C@@H](CS)C(=O)N[C@@H](Cc1ccc(O)cc1)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CCCNC(=N)N)C(=O)N[C@@H](CS)C(=O)N[C@@H](CCCNC(=N)N)C(=O)O

1 : Muta T, et al. Tachyplesins isolated from hemocytes of Southeast Asian horseshoe crabs (Carcinoscorpius rotundicauda and Tachypleus gigas): identification of a new tachyplesin, tachyplesin III, and a processing intermediate of its precursor. J Biochem. 1990; 108:261-6. doi: 10.1093/oxfordjournals.jbchem.a123191

Paper title : Tachyplesins isolated from hemocytes of Southeast Asian horseshoe crabs (Carcinoscorpius rotundicauda and Tachypleus gigas): identification of a new tachyplesin, tachyplesin III, and a processing intermediate of its precursor.

Doi : https://doi.org/10.1093/oxfordjournals.jbchem.a123191

Abstract : Tachyplesins and their analogs are antimicrobial peptides composed of 17 or 18 amino acid residues present abundantly in acid extracts of hemocyte debris of horseshoe crabs. We purified here tachyplesin isopeptides from hemocytes of two species of Southeast Asian horseshoe crabs, Carcinoscorpius rotundicauda and Tachypleus gigas, and determined their amino acid sequences. The major tachyplesin isolated from both species was identified, respectively, as tachyplesin I, which had previously been found in hemocytes of the Japanese horseshoe crab (Tachypleus tridentatus). The yield from both species was very high (more than 70 mg per 100 g wet weight of hemocytes), i.e., comparable with that from T. tridentatus. In addition to tachyplesin I, a new tachyplesin isopeptide, named tachyplesin III, was also isolated from T. gigas hemocytes, in which an arginine replaced the 15th lysine of tachyplesin I. The carboxyl-terminal residue of the isolated tachyplesins I and III was confirmed, respectively, to be an arginine alpha-amide by chemical analysis. Furthermore, a tachyplesin peptide derivative with a carboxyl-terminal extension of glycine-lysine was newly found in the hemocytes of C. rotundicauda. It appeared to be an intermediate derived from a tachyplesin precursor during processing to the mature form.