KATAKAI Ryoichi Faculty of Engineering, Gunma University, Professor, 工学部, 教授 (10008500)
SATO Kumiko Gunma University School of Health Sciences, Professor, 医学部, 教授 (80008268)
KANO Sigeyuki Research Institute, International Medical Center of Japan, Director, 適性技術開発・移転研究部, 部長 (60233912)
YOSHIDA Masaru Japan Atomic Energy Research Institute, Chief Investigator, 高崎研究所, 主任研究員
OKU Hiroyuki Faculty of Engineering, Gunma University, Assistant Professor, 工学部, 助手 (20301749)
In this research, we synthesized the following two peptides first, Boc-GIGNPNAGIG-Oet and cyclo[(NPNAGAG)ィイD22ィエD2] with regard to the basic structure of the circum sporozoite protein, (NANP)ィイD2nィエD2 Structure of the peptides were analyzed by Nuclear Magnetic Resonance, Fourier-transform Infraredspectrum, and Circular Dichroism Spectroscopy, and it was revealed that those peptides had β-structure within the polypeptides which would work as an appropriate antigenic structure for the detection of the malarial antibody. When we examined their antigenicity by fluorescence-ELISA by applying malaria patients' sera from Thailand, quite a nice reaction was observed suggesting their potential importance as diagnostic materials.
Another synthetic polypeptides studied in this research was a part of enolase, a glycolytic enzyme. We analyzed the tertially structure of enolase with reference to the crystal structure of yeast enolase. The identity of the peptides were calculated as 61% and we concluded that we could built up the structure of Plasmodial enolase by computer graphics. Then we chose a part of the polypeptides which consisted of Asn with β-turn structure: GFAPNILNANEALDLL. The synthetic polypeptides of this helical structure was also proved to be a good antigenic molecule for the detection of malarial antibody. It is also proved that this molecule was highly reactive against the sera from complicated malaria patients, but less reactive against those from mild malaria patients. We, thus, regarded this molecule as a good material for us to develop appropriate diagnostic technology not only for individuals, but also for the evaluation of epidemiological situation of endemic areas.