Studies on the Structure−Activity Relationship of Endostatin:  Synthesis of Human Endostatin Peptides Exhibiting Potent Antiangiogenic Activities

Abstract

The aim of the present research was to study the relationship between chemical structure and antiangiogenic activity of endostatin. Four peptides, containing about 40 amino acid residues, designed to cover nearly the whole sequence of endostatin, were synthesized by the solid-phase method. They were termed Fragment I (sequence 6-49), II (sequence 50-92), III (sequence 93-133), and IV (sequence 134-178), with the latter bearing the original disulfide bond Cys135-Cys165. These peptides were tested for their ability to inhibit endothelial cell proliferation, migration, and both in vitro and in vivo angiogenesis assays in matrigel. Fragments I and IV inhibited cell proliferation and cell migration with a potency and an efficacy higher than that of the full length endostatin. Fragment I was also active in inhibiting in vitro the formation of tubules and in vivo the vascularization of the matrigel. Fragments II and III were devoid of antiangiogenic activity. We propose to use the peptides 6-49 and 134-178 as angiogenesis inhibitors in substitution of full length endostatin, in therapeutic applications for cancer, rheumatoid arthritis, and retinopathies.

A 27-Amino-Acid Synthetic Peptide Corresponding to the NH2-Terminal Zinc-Binding Domain of Endostatin Is Responsible for Its Antitumor Activity

“…Several groups have shown that peptides derived from endostatin have antiangiogenic effects (29,(37)(38)(39)(40)). An NH 2 -terminal peptide composed of amino acids 6 to 49 (lacking the Zn-binding histidines) has inhibited endothelial cell proliferation and migration (37,38).…”

“…An NH 2 -terminal peptide composed of amino acids 6 to 49 (lacking the Zn-binding histidines) has inhibited endothelial cell proliferation and migration (37,38). A Matrigel assay using this peptide has resulted in the inhibition of angiogenesis in vivo.…”

An Endostatin-derived Peptide Interacts with Integrins and Regulates Actin Cytoskeleton and Migration of Endothelial Cells

“…In a recent study four endostatin-derived peptides spanning amino acids 6 -178 were used to identify regions of the protein with anti-angiogenic potential (37). The study revealed a peptide containing amino acids 6 -49 to be capable of inhibiting human umbilical vein-derived endothelial cell proliferation and migration and effective in inhibiting angiogenesis in vivo.…”

“…This is most likely due to differences in secondary structure of peptides of different lengths (38). Furthermore, the peptides with anti-angiogenic activity (37) do not contain the specific arginine residues found to be important for the biological activity of endostatin, suggesting that additional novel domains could be involved in the activity of endostatin.…”

Targeted Delivery of an Antibody–Mutant Human Endostatin Fusion Protein Results in Enhanced Antitumor Efficacy

“…Four synthetic peptides corresponding to the sequences 6-49 (I), 50-92 (II), 93-133 (III), and 134-178 (IV) of human endostatin have been examined for their ability to inhibit endothelial cell proliferation, migration, and both in vitro and in vivo angiogenesis (31,32). Fragment I was found to be antiangiogenic whereas unexpectedly, fragment III exhibited a proangiogenic activity, increased endothelial cell migration and neovascularization, and enhanced the angiogenic response to vascular endothelial growth factor in a corneal pocket assay.…”