Studies on Protein Structure and Physiological Function of Ovalbumin with Property of Molecular Chaperon

具有分子伴侣性质的卵清蛋白的蛋白质结构和生理功能研究

• 批准号: 13660301
• 负责人: SUGIMOTO Yasushi
• 金额: $ 2.24万
• 依托单位: Kagoshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13660301/
• 关键词: ovalbumin; S-ovalabumin; serpin; organogenesis; molecular chaperon; chick embryo; knockout; 鶏発生; DSC; ニワトリ; プロテアーゼインヒビター; 熱安定性; 構造変化; タンパク構造; 胚発生; ovalbumin; S-ovalabumin; serpin; organogenesis; molecular chaperon; chick embryo; knockout; 鶏発生; DSC; ニワトリ; プロテアーゼインヒビター; 熱安定性; 構造変化; タンパク構造; 胚発生

Ovalbumin, which is the major albumen protein having carbohydrate and phosphate residues, belongs to the serine protease inhibitor superfamily. However, ovalbumin is not inhibitory against proteases, and, therefore, its function remains uncertain except for a possible contribution as a nutrient source. We reported previously that ovalbumin molecules were transported from albumen to the embryo via egg yolk, amniotic fluid, serum etc, without degradation, and distributed in various organs including the central nervous system, while these molecules undergo changes in secondary conformation and attain a heat-stable state (this state of molecules will be called 'HS-ovalbumin'). Here we showed that HS-ovalbumin is distinguishable from the known heat-stable molecular form named S-ovalbumin by a presently prepared monoclonal antibody and that HS-ovalbumin arises from its native form (N-ovalbumin) in developing eggs. We also established in vitro culture conditions, under which embryos isolated from eggs at and after stage 4 of embryogenesis could be successfully cultured for at least 24 h. When the remnant fractions of endogenous ovalbumin was neutralized by using a polyclonal antibody, the isolated embryos could not grow normally, being particularly irregular in the brain tissue, which hardly undergo the neural tube closure occurring in normal embryos at stage 9. The embryos were rescued from the aberration by adding an excess amount of ovalbumin to the medium at an early period of culture. HS-ovalbumin showed a higher rescue rate than the N-and S-counterparts. Our findings demonstrated that ovalbumin is indispensable to, and probably plays a crucial role in, the embryonic organogenesis.

椭圆蛋白是含有碳水化合物和磷酸盐残基的主要蛋白，属于丝氨酸蛋白酶抑制剂超家族。但是，卵蛋白不是抑制蛋白酶的，因此，除了可能作为营养源的贡献外，其功能仍然不确定。 We reported previously that ovalbumin molecules were transported from albumen to the embryo via egg yolk, amniotic fluid, serum etc, without degradation, and distributed in various organs including the central nervous system, while these molecules undergo changes in secondary conformation and attain a heat-stable state (this state of molecules will be called 'HS-ovalbumin').在这里，我们表明，HS-卵蛋白与目前制备的单克隆抗体称为S-卵蛋白的已知热稳定分子形式可以区分，而HS-卵蛋白在发育中的鸡蛋中源自其天然形式（N-Overbumin）。我们还建立了体外培养条件，在该条件下，在胚胎发生的第4阶段和第4阶段从卵中分离出来，可以成功培养至少24小时。当通过使用多克隆抗体中内源性卵巢蛋白的残留分数中和时，孤立的胚胎无法正常生长，在脑组织中尤为不规则，在9阶段，在正常的胚胎中几乎不会在embryos中恢复过多的胚胎。 HS-overbumin的救援率高于N和S-Counterparts。我们的发现表明，椭圆蛋白对于胚胎器官发生不可或缺，并且可能起着至关重要的作用。