Van der Kraak G, Suzuki K, Peter R E, Itoh H, Kawauchi H
Department of Zoology, University of Guelph, Ontario, Canada.
Gen Comp Endocrinol. 1992 Feb;85(2):217-29. doi: 10.1016/0016-6480(92)90005-5.
Two gonadotropins, GtH I and GtH II, were extracted with 35% ethanol-10% ammonium acetate, pH 6.1, from female common carp pituitary glands and purified by ion-exchange chromatography on a DE-52 column followed by gel filtration on a Sephadex G-75 column. Molecular weights of GtH I and GtH II as determined by SDS-PAGE were 45,000 and 35,000, respectively. Both GtHs dissociate into two subunits following reduction with beta-mercaptoethanol. These subunits contain different N-terminal amino acids (Tyr and Gly for GtH I; Tyr and Ser for GtH II). GtH I was acid stable and did not dissociate into subunits following treatment with 0.1% trifluoroacetic acid; GtH II readily dissociated into subunits by this treatment. GtH I and GtH II have distinct elution profiles on reverse-phase HPLC. The N-terminal amino acid sequence of the beta-subunit of GtH II was identical to that of common carp maturational GtH described by other workers suggesting that GtH I is a newly identified molecule. This was supported by radioimmunoassay analysis. GtH II and a common carp maturational GtH preparation (F11 cGtH; Peter et al., 1982, J. Interdiscipl. Cycle Res. 13, 229-239) had similar immunological activity in tests with antisera to the beta-subunit of maturational GtH whereas GtH I had low (less than 6%) cross-reactivity. GtH I, GtH II, and F11 cGtH were equipotent in tests with antisera to the alpha-subunit of maturational GtH suggesting these molecules contain a similar alpha-subunit. In vitro bioassays using goldfish revealed that GtH I and GtH II share the same spectrum of biological activities causing stimulation of ovarian and testicular steroidogenesis and induction of oocyte final maturation. The demonstration of two chemically distinct GtHs in common carp is similar to what has been described for chum and coho salmon.
用pH 6.1的35%乙醇-10%醋酸铵从雌性鲤鱼脑垂体中提取出两种促性腺激素，即促性腺激素I（GtH I）和促性腺激素II（GtH II），然后通过在DE-52柱上进行离子交换色谱，接着在Sephadex G-75柱上进行凝胶过滤来纯化。通过SDS-PAGE测定，GtH I和GtH II的分子量分别为45,000和35,000。用β-巯基乙醇还原后，两种GtH均解离为两个亚基。这些亚基含有不同的N端氨基酸（GtH I为Tyr和Gly；GtH II为Tyr和Ser）。GtH I对酸稳定，用0.1%三氟乙酸处理后不会解离为亚基；GtH II经此处理后很容易解离为亚基。GtH I和GtH II在反相HPLC上有不同的洗脱图谱。GtH II的β亚基的N端氨基酸序列与其他研究者描述的鲤鱼成熟促性腺激素的序列相同，这表明GtH I是一个新发现的分子。放射免疫分析也支持了这一点。在使用成熟促性腺激素β亚基抗血清的试验中，GtH II和一种鲤鱼成熟促性腺激素制剂（F11 cGtH；Peter等人，1982年，《跨学科周期研究杂志》13卷，229 - 239页）具有相似的免疫活性，而GtH I的交叉反应性较低（小于6%）。在使用成熟促性腺激素α亚基抗血清的试验中，GtH I、GtH II和F11 cGtH具有同等效力，这表明这些分子含有相似的α亚基。使用金鱼进行的体外生物测定表明，GtH I和GtH II具有相同的生物活性谱，可刺激卵巢和睾丸的类固醇生成并诱导卵母细胞最终成熟。在鲤鱼中发现两种化学性质不同的GtH与在马苏大麻哈鱼和银大麻哈鱼中所描述的情况相似。
