Department of Gamete and Embryo Biology, Semen Biology Group, Institute of Animal Reproduction and Food Research, 10-747 Olsztyn, Poland.
Fish Shellfish Immunol. 2010 Jul;29(1):66-74. doi: 10.1016/j.fsi.2010.02.015. Epub 2010 Feb 26.
Transferrin (Tf) in fish is recognized as a component of non-specific humoral defense mechanisms against bacteria. It is a major protein of common carp seminal plasma but its structure and localization in carp testis is unknown. In this study we developed a simple and efficient three-step purification procedure consisting of affinity chromatography (Con A-Sepharose), hydrophobic interaction chromatography (Phenyl Sepharose) and gel filtration (Superdex 200). The molecular mass of Tf has been determined to be 73.6 kDa and isoelectric point 5.1. The peculiar characteristics of carp transferrin were the lack of carbohydrate component and binding of iron ions by only one functional iron-binding site. Western blot analysis revealed a strong similarity of carp seminal plasma Tf to carp blood Tf and Tf from seminal plasma of other cyprinids but a lower similarity to salmonid and percid fishes. Tf was localized to the blood vessels of the carp testis which strongly suggest that most Tf of carp seminal plasma originates from blood. In conclusion, seminal plasma Tf has a unique structure and is similar or identical to blood Tf.
转铁蛋白（Tf）在鱼类中被认为是针对细菌的非特异性体液防御机制的组成部分。它是鲤鱼精液浆中的主要蛋白质，但在鲤鱼睾丸中的结构和定位尚不清楚。在这项研究中，我们开发了一种简单有效的三步纯化程序，包括亲和层析（Con A-Sepharose）、疏水性相互作用层析（Phenyl Sepharose）和凝胶过滤（Superdex 200）。Tf 的分子量已确定为 73.6 kDa，等电点为 5.1。鲤鱼转铁蛋白的独特特征是缺乏碳水化合物成分，并且仅通过一个功能铁结合位点结合铁离子。Western blot 分析表明，鲤鱼精液浆 Tf 与鲤鱼血液 Tf 和其他鲤科鱼类精液浆 Tf 具有很强的相似性，但与鲑鱼和鲈形目鱼类的相似性较低。Tf 定位于鲤鱼睾丸的血管中，这强烈表明鲤鱼精液浆中的大多数 Tf 来自血液。总之，精液浆 Tf 具有独特的结构，与血液 Tf 相似或相同。
