Preparation and Immunological Study for Oligopeptide-Dendrimer Conjugates as Multiple Antigen Peptide for p53 Mutant

2005 Fiscal Year Final Research Report Summary

• Project/Area Number: 16550140
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Chemistry related to living body
• Research Institution: Akita University
• Principal Investigator: JIKEI Mitsutoshi Akita University, Department of Material-process Engineering & Applied Chemistry for Environments, Associate Professor, 工学資源学部, 助教授 (70251618)
• Co-Investigator(Kenkyū-buntansha): ITOH Hideaki Akita University, Department of Material-process Engineering & Applied Chemistry for Environments, Professor, 工学資源学部, 教授 (80168369)
• Project Period (FY): 2004 – 2005
• Keywords: dendrimer / anti-peptide antibody / aromatic polyamide / p53 mutant / antigen-antibody interaction

Research Abstract

Dendrimers are characterized by unique three-dimensional architecture and multiple functional groups located at the periphery. Among them, aromatic polyamide dendrimers are readily prepared and have strong hydrophobicity and hydrogen-bond-based interaction caused by the aromatic amide structure. The protein, p53 mutant, is one of the most frequently observed proteins in cancer cells. The p53 mutant accelerates growth of tumor cells although wild type p53 is known as a suppressor for tumors. In this work, we have prepared oligopeptide-polyamide dendrimer conjugates as multiple antigen peptide in order to prepare high-titer antibodies for p53 mutant.
As a preliminary study, a small protein, heat shock protein 10(HSP10), was conjugated to the terminal of polyamide dendrimers. The HSP10-dendrimer conjugates showed antigen-antibody interaction against anti-HSP10 antibody. The fact implies that the hydrophilic segment of HSP10 is exposed in water and the dendrimer acts as a carrier for hydrophilic peptides.
Oligopeptide containing a hot spot of p53 mutation (R248Q) was covalently connected to tetra-valent aromatic polyamide dendrimers via divergent or convergent approach. The formation of tetra-substituted peptide-polyamide conjugates was confirmed by the convergent approach. The resulting conjugates were soluble in water due to strong hydrophilic nature of the peptides. Dimer formation of the conjugates in water was confirmed by GPC measurements. Immune response of the conjugates by rabbits is not successful at this moment and still under investigation. The conjugation to large polyamide dendrimers which have stronger hydrophobicity might be a suitable choice from the view point of the preparation of antibodies.