三种鲟科鱼类和两种鲑科鱼类卵黄免疫球蛋白性质的比较

从施氏鲟(Acipenser schrencki)、小体鲟(Acipenser ruthenus)、西伯利亚鲟(Acipenser baeri)、哲罗鲑(Hucho taimen)和金鳟(Oncorhynchus mykiss)五种鱼类卵黄中分离、纯化Ig,并对其分子结构进行了初步研究。结果表明:五种鱼类卵中Ig的分子量分别为施氏鲟524kD、小体鲟468kD、西伯利亚鲟475kD、哲罗鲑为490kD,金鳟498kD,其Ig重链的相对分子量相同,约为97kD。轻链的相对分子量各不相同,施氏鲟为27kD,小体鲟28.5kD,西伯利亚鲟30kD,哲罗鲑28.5kD和金鳟16kD。其中西伯利亚鲟、施氏鲟和小体鲟Ig等电点约为5.85,哲罗鲑和金鳟的Ig等电点约为6.55,其蛋白质结构上具有一定的相似性,且均为糖蛋白

Comparison of immunoglobulins in egg yolk of three species of sturgeons and two species of salmonids

In this paper, immunoglobulins (Igs) were purified respectively from egg yolk of Amur sturgeon Acipenser schrencki, sterlet A.ruthenus, Siberian sturgeon A.baeri,taimen Hucho taimen and golden rainbow trout Oncorhynchus mykiss. Their chemical, physical, and antigenc characteristics were studied by high speed centrifugation and gel filtration chromatography. Molecular weights of immunoglobulin from Amur sturgeon, Sterlet, Siberian sturgeon, Taimen and golden rainbow trout were 524, 468, 475, 490 and 498 kD respectively. After SDS-PAGE, immunoglobulin of the five species of fishes appeared as two bands, representing heavy chains and light chains respectively. The molecular weight of the heavy chains of five fishes was about 97 kD, and the molecular weight of the light chains was 27 kD for Amur sturgeon, 28.5 kD for Sterlet, 30 kD for Siberian sturgeon, 28.5 kD for Taimen and 16 kD for golden rainbow trout. Immunoglobulins of these five species were confirmed to be glycoproteins by staining with Molecular Proes' Pro-Q~ Emerald 300 Glycoprotein Gel stain. The pI of immunoglobulin of fishes were 5.85 for Amur sturgeon, Sterlet and Siberian sturgeon, and 6.55 for Taimen and gold rainbow trout.Immunoglobulin from egg yolk and serum of the Amur sturgeon showed identical antigencity. Antiserum against Ig in egg yolk of the Amur sturgeon also cross-reacted with Igs in egg yolk of other sturgeons and cross-reacted weakly with Igs from the salmonid fishes suggesting that Igs in egg yolk of fish may not be species specific.