Peptide name : HHPHG

Source/Organism : Synthetic Peptide

Linear/Cyclic : Linear

Chirality : L

Peptide length: 5

C-terminal modification: Linear

N-terminal modification : Free

Non-natural peptide information: None

Assay type : Tropomyosin binding assay

Assay time : Not found

Activity : IC50 : 92 µM

Cell line : Not found

Cancer type : Tumor

Other activity : Not found

Amino acid composition bar chart :

Molecular mass : 583.5997 Dalton

Aliphatic index : 0

Instability index : -18.5

Hydrophobicity (GRAVY) : -2.32

Isoelectric point : 7.0224

Charge (pH 7) : 0.0216

Aromaticity : 0

Molar extinction coefficient (cysteine, cystine): (0, 0)

Hydrophobic/hydrophilic ratio : 0.66666666

hydrophobic moment : -0.609

Missing amino acid : W,T,I,M,E,K,F,D,N,C,R,Q,S,Y,L,A,V

Most occurring amino acid : H

Most occurring amino acid frequency : 3

Least occurring amino acid : P

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0, 0.4, 0)

SMILES Notation: N[C@@H](Cc1c[nH]cn1)C(=O)N[C@@H](Cc1c[nH]cn1)C(=O)N1CCC[C@H]1C(=O)N[C@@H](Cc1c[nH]cn1)C(=O)NCC(=O)O

1 : Doñate F, et al. Peptides derived from the histidine-proline domain of the histidine-proline-rich glycoprotein bind to tropomyosin and have antiangiogenic and antitumor activities. Cancer Res. 2004; 64:5812-7. doi: 10.1158/0008-5472.CAN-04-0440

Paper title : Peptides derived from the histidine-proline domain of the histidine-proline-rich glycoprotein bind to tropomyosin and have antiangiogenic and antitumor activities.

Doi : https://doi.org/10.1158/0008-5472.CAN-04-0440

Abstract : The antiangiogenic activity of the multidomain plasma protein histidine-proline-rich glycoprotein (HPRG) is localized to its histidine-proline-rich (H/P) domain and has recently been shown to be mediated, at least partially, through binding to cell-surface tropomyosin in fibroblast growth factor-2-activated endothelial cells (X. Guan et al., Thromb Haemost, in press). HPRG and its H/P domain, but not the other domains of HPRG, bind specifically and with high affinity to tropomyosin. In this study, we characterize the interaction of the H/P domain with tropomyosin and delineate the region within the H/P domain responsible for that interaction. The H/P domain of HPRG consists mostly of repetitions of the consensus sequence [H/P][H/P]PHG. Applying an in vitro tropomyosin binding assay, we demonstrate that the synthetic peptide HHPHG binds to tropomyosin in vitro and inhibits angiogenesis and tumor growth in vivo. The affinity for tropomyosin increases exponentially upon multimerization of the HHPHG sequence, with a concurrent increase in antiangiogenic activity. Specifically, the tetramer (HHPHG)4 has significant antiangiogenic activity in the Matrigel plug model (IC50 approximately 600 nm) and antitumor effects in two syngeneic mouse tumor models. Thus, we show that a 16-mer peptide analogue mimics the antiangiogenic activity of intact HPRG and is also able to inhibit tumor growth, suggesting that cell surface tropomyosin may represent a novel antiangiogenic target for the treatment of cancer.