EFFECTS OF VARIOUS PROTEASE INHIBITORS ON STARFISH OOCYTE MATURATION
EFFECTS OF VARIOUS PROTEASE INHIBITORS ON STARFISH OOCYTE MATURATION
复制标题
各种蛋白酶抑制剂对海星卵母细胞成熟的影响
DOI：
10.2220/biomedres.4.139
复制
发表时间：
1983
影响因子：
1.2
通讯作者：
H. Kanatani
中科院分区：
文献类型：
--
作者：
K. Sano;H. Kanatani
Effects of various protease inhibitors on starfish oocyte maturation were examined. N-Benzoyl-L-tyrosine ethyl ester, a synthetic substrate for chymotrypsin, was the most potent inhibitor of the oocyte maturation among the synthetic protease inhibitors examined. Chymostatin, an inhibitor specific for chymotrypsin~li1<e serine proteases and some thiol proteases, was the most potent inhibitor among the inhibitors of microbial origin examined. Chymostatin did not inhibit maturation induced by the injection of maturation promoting factor (MPF). It exerted its inhibitory effect only when it was applied within the hormone-dependent (H.D.) period (the minimum period wherein 1-methyladenine (1-MeAde) is required). Exposure of oocytes for 1 min to chymostatin at difi°erent times during the hormone-dependent period demonstrated that the most potent inhibition occurred in the latter part of this period. The results suggest that a chymotrypsin-like serine protease exists in oocytes and is involved in the formation of maturation promoting factor later in the hormonedependent period. Oocyte maturation of starfish is induced by 1-methyladenine (1-MeAde) (10, 13), which is produced in the follicle cells by the action of a gonad-stimulating substance (GSS) secreted by the supporting cells of the nervous system (2, 8, 12.). 1-MeAde acts on the surface of the oocytes(11) and produces rnaturation promoting factor (MPF) in the cytoplasm, which induces germinal vesicle breakdown (GVBD) when injected into immature oocytes (16). Natural oocyte maturation of the starfish was inhibited by leupeptin and antipain, protease inhibitors of microbial origin (1, 15). However, MPF-induced maturation was not inhibited by leupeptin (15). In this paper, we report the results of investigations on the action of various protease inhibitors in inhibiting meiotic maturation in 1Present address: Developmental Biology Laboratory, Department of Plastic Surgery, Kitasato University School of Medicine, Sagamihara 228, Japan starfish oocytes. From these studies, further information on the formation of MPF was derived. MATERIALS AND METHODS Starfishes, Asierina _pecri'mfera were collected from Kanagawa and Aomori, and Asrerias anmi'ens:'.s‘ from Kanagawa, during their breeding season and kept in laboratory aquaria with circulating seawater at 14°C. Seawater used for the experiments was a modified Van’t Hoff’s artificial seawater (ASW), i.e., 460 mM NaCl, 10.1 mM KCI, 9.2 n1M CaCl2, 35.9 mM MgCl2, and 17.5 mM MgSO4, buffered to pH 8.2 with 20 ml\/I borate-NaOH. Calcium-free seawater (CaFSW) was made by replacing CaCl2 with NaCl. Isolation of Oocytes Fully grown oocytes were obtained by dissociating ovaries with forceps in CaFSW. After
