| Co-Investigator(Kenkyū-buntansha) |
MATSUI Masabumi Kyoto University, Faculty of Gen. Edu. Assis, 教養部, 助手 (40101240)
ISHIGAKI Haruo Waseda University, School of Education Prof, 教育学部, 教授 (60063492)
KIKUYAMA Sakoe Waseda University, School of Education Prof, 教育学部, 教授 (20063638)
MATSUI Masabumi Kyoto University, Faculty of Gen. Edu. Assis (40101240)
MATSUI Masabumi Kyoto University, Faculty of Gen. Edu. Assis (40101240)
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| Research Abstract |
1) We isolated two species of glycoproteins from pituitary glands of the toad, Bufo japonicus, and identified them as follicle stimulating hormone (FSH) and luteinizing hormone (LH) from their biological activities. Using antisera raised against these hormones, we examined cross reactivity of gonadotropins of various vertebrates. Bullfrog gonadotropins showed relatively high crossreactivity, but mammalian and avian gonadotropins did slightly. Teleostean gonadotropins did not cross-react completely.
2) The testicular gonadotropin receptor in the bullfrog, Rana catesbeiana, bound both bullfrog FSH and bullfrog LH with the same affinity when they were tested independently. However, under the presence of both hormone, the binding affinity of LH was in creased as a function of the concentration of FSH. This positive cooperative mechanism suppresses partially the competitive inhibition of LH action by FSH.
3) The proline content in the beta-subunit of LH varied among classes of vertebrate vigorously, from about 6% to about 20%, while that of FSH was varied in a small range or almost constant. The amphibian LH beta-subunit showed the smallest content. The positions of the proline residues are considered to be mostly conserved throughout the course of the vertebrate evolution.
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