Growth factor binding molecules
Growth factor binding molecules having a plurality of peptide loops attached to a non-peptide organic scaffold, preferably having pseudo-six amino acid peptide loops with four amino acid sidechains. The growth factor binding molecules specifically bind various growth factors and are suitable for treating a subject having tumors or restinosis. In one embodiment a platelet-derived growth factor binding molecule is disclosed that is used to inhibit tumor growth and angiogenesis in solid tumors.
1. A growth factor binding compound, of the general structure:
wherein R is n-butyl, n-propyl, benzyl, (C 1 –C 12 ) alkyl, (C 7 –C 18 ) aralkyl, (C 6 –C 18 ) aryl, (C 1 –C 12 ) alkenyl, (C 7 –C 18 ) aralkenyl, or (C 1 –C 12 ) alkylether, and X are independently cyclic peptide loops of the general structure:
wherein R 1 , R 2 , R 3 , and R 4 are each amino acid side chains that define a tetrapeptide, wherein said tetrapeptide is covalently attached at the amino and carboxy termini of said tetrapeptide to a 3-aminomethyl-5-aminobenzamide linking group, and wherein said tetrapeptide is selected from the group consisting of GDFD (SEQ ID NO. 1), GDDD (SEQ ID NO. 2), D-ADGD (SEQ ID NO. 3), GDLD (SEQ ID NO. 4), GDAD (SEQ ID NO. 5), GDGY (SEQ ID NO. 6), ADGD (SEQ ID NO. 7), GDSD (SEQ ID NO. 8), GKGF (SEQ ID NO. 9), GKGK (SEQ ID NO. 10), GDND (SEQ ID NO. 11), PDGD (SEQ ID NO. 12), GDDG (SEQ ID NO. 13), and GDDY (SEQ ID NO. 14).
2. The compound of claim 1 , in which said growth factor is a platelet derived growth factor, and wherein said tetrapeptide is GDGY (SEQ ID NO. 6).
3. The compound of claim 1 wherein said growth factor is vascular endothelial growth factor and wherein said tetrapeptide is GKGK (SEQ ID NO. 10) or GDGY GDGY (SEQ ID NO. 6).
4. The compound of claim 1 wherein said growth factor is acidic fibroblast growth factor and wherein said tetrapeptide is GDDD (SEQ ID NO. 2), GKGK (SEQ ID NO. 10), GDDG (SEQ ID NO. 13) or GDGY (SEQ ID NO. 6).
5. The compound of claim 1 wherein said growth factor is insulin-like growth factor-1 and wherein said tetrapeptide is GDDG (SEQ ID NO. 13).
6. A composition comprising the compound of claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.