Udby Lene, Johnsen Anders H, Borregaard Niels
Granulocyte Research Laboratory, Department of Hematology, Copenhagen University Hospital, Rigshospitalet, Denmark.
Biochim Biophys Acta. 2010 Apr;1800(4):481-5. doi: 10.1016/j.bbagen.2010.01.011. Epub 2010 Jan 28.
CRISP-3 was previously shown to be bound to alpha(1)B-glycoprotein (A1BG) in human serum/plasma. All mammalian sera are supposed to contain A1BG, although its presence in rodent sera is not well-documented. Since animal sera are often used to supplement buffers in experiments, in particular such that involve cell cultures, binding proteins present in sera might interfere in the experiments.
We examined sera from five different animal species for CRISP-3 binding proteins using gel filtration and ligand blotting. We developed a rapid method for isolation of proteins that bind to human CRISP-3 and identified the isolated proteins by mass spectrometry and N-terminal sequencing.
We identified A1BG as a CRISP-3 binding protein in sera from cow, horse and rabbit. CRISP-3 bound kininogen 1 in mouse serum, whereas rat serum showed no CRISP-3 binding activity. In equine serum, we furthermore detected a possible CRISP, already bound to A1BG.
It seems to be a common mechanism that A1BGs bind CRISPs, also across species. Apart from the possible physiological implications hereof, complex binding of CRISPs by A1BG (and other proteins) may interfere with the detection and function of CRISPs, when these are studied in the presence of animal sera.
先前研究表明，人血清/血浆中的CRISP-3与α(1)B-糖蛋白（A1BG）结合。所有哺乳动物血清都应含有A1BG，尽管其在啮齿动物血清中的存在尚无充分文献记载。由于动物血清常用于补充实验缓冲液，特别是在涉及细胞培养的实验中，血清中存在的结合蛋白可能会干扰实验。
我们使用凝胶过滤和配体印迹法检测了来自五种不同动物物种的血清中的CRISP-3结合蛋白。我们开发了一种快速方法来分离与人CRISP-3结合的蛋白，并通过质谱和N端测序鉴定分离出的蛋白。
我们在牛、马和兔的血清中鉴定出A1BG是一种CRISP-3结合蛋白。CRISP-3与小鼠血清中的激肽原1结合，而大鼠血清未显示出CRISP-3结合活性。此外，在马血清中，我们检测到一种可能已与A1BG结合的CRISP。
A1BG结合CRISP似乎是一种跨物种的常见机制。除了可能的生理影响外，当在动物血清存在的情况下研究CRISP时，A1BG（和其他蛋白质）对CRISP的复杂结合可能会干扰CRISP的检测和功能。
