Siberian Division of Russian Academy of Sciences, Institute of Chemical Biology and Fundamental Medicine, Novosibirsk, Russia.
Siberian Division of Russian Academy of Sciences, Institute of Cytology and Genetics, Novosibirsk, Russia.
J Mol Recognit. 2019 Jul;32(7):e2777. doi: 10.1002/jmr.2777. Epub 2019 Feb 13.
Lactoferrin (LF) is an Fe -binding glycoprotein first recognized in milk and then in other epithelial secretions and barrier body fluids to which many different functions have been attributed to LF, including protection from iron-induced lipid peroxidation, immunomodulation, cell growth regulation, DNA and RNA binding, as well as transcriptional activation, еtс. The polyfunctional physiological role of LF is still unclear, but it has been suggested to be responsible for primary defense against microbial and viral infections. Here, we present the first evidence that LF preparations isolated from milk of 18 cows of different breeds possess various levels of metal-dependent DNase and metal-independent RNase activities. For univocal assignment of DNase and RNase activities to cow LF, it was subjected to SDS-PAGE using gels with copolymerized calf thymus DNA or polymeric yeast RNA. In situ analysis was revealed DNase and RNase activities only in the gel zones corresponding to homogeneous LF. In contrast to human LF, cow LF possesses a relatively low cytotoxicity towards human tumor cells. The discovery that cow LF has these activities may contribute to understanding the multiple physiological functions of this extremely polyfunctional protein, including its protective role against microbial and viral infections. The computational spatial model of cow LF complex with DNA was obtained: according to the model positively charged residues of LF contact with DNA.
乳铁蛋白 (LF) 是一种 Fe 结合糖蛋白，最初在牛奶中发现，然后在其他上皮分泌物和屏障体液中发现，LF 具有许多不同的功能，包括防止铁诱导的脂质过氧化、免疫调节、细胞生长调节、DNA 和 RNA 结合以及转录激活等。LF 的多效生理作用尚不清楚，但它被认为是对抗微生物和病毒感染的主要防御机制。在这里，我们首次证明，来自 18 头不同品种奶牛的乳中分离得到的 LF 制剂具有不同水平的金属依赖性 DNA 酶和非依赖性 RNA 酶活性。为了明确将 DNA 酶和 RNA 酶活性归因于牛 LF，我们使用共聚合小牛胸腺 DNA 或聚合酵母 RNA 的凝胶进行 SDS-PAGE。原位分析仅在对应于同质 LF 的凝胶区域中揭示了 DNA 酶和 RNA 酶活性。与人类 LF 不同，牛 LF 对人肿瘤细胞的细胞毒性相对较低。发现牛 LF 具有这些活性可能有助于理解这种多功能蛋白的多种生理功能，包括其对微生物和病毒感染的保护作用。获得了牛 LF 与 DNA 复合物的计算空间模型：根据模型，LF 的正电荷残基与 DNA 接触。
