Adolf G R, Maurer-Fogy I, Kalsner I, Cantell K
Ernst Boehringer-Institut für Arzneimittelforschung, Bender & Co Ges mbH, Vienna, Austria.
J Biol Chem. 1990 Jun 5;265(16):9290-5.
Human interferon omega 1 (IFN-omega 1 = IFN-alpha II1) is a recently discovered protein structurally related to IFN-alpha and -beta; the biological activities of IFN-omega 1 and its physiological role are not known to date. We have purified IFN-omega 1 from preparations of human leukocyte IFN, derived from peripheral blood leukocytes induced with Sendai virus, by two sequential cycles of monoclonal antibody affinity chromatography. The resulting protein was at least 95% pure as determined by reverse-phase high performance liquid chromatography and showed an Mr of 24,500 upon sodium dodecyl sulfate-gel electrophoresis (theoretical Mr, 19,984). Amino acid sequence analysis revealed that only about 40% of the molecules have the NH2 terminus expected on the basis of the sequence similarity to IFN-alpha, whereas the others contain two additional amino acids. This difference probably results from variable cleavage of the pre-protein by the signal peptidase. No evidence for COOH-terminal heterogeneity was found. Essentially all IFN-omega 1 molecules are glycosylated; enzymatic deglycosylation resulted in a reduction of the Mr to 20,500. Experiments using several plant lectins indicated the presence of biantennary complex oligosaccharides containing neuraminic acid. Two major peaks were observed upon chromatofocusing, with isoelectric points of 8.1 and 8.5. The specific antiviral activity of purified IFN-omega 1 assayed on human cells was determined to be 2.7 x 10(8) IU/mg, similar to that of other human class I IFNs; potent antiviral activity was also observed on cells of bovine and ovine but not of equine or murine origin.
人ω1干扰素（IFN-ω1 = IFN-α II1）是一种最近发现的蛋白质，其结构与IFN-α和-β相关；迄今为止，IFN-ω1的生物学活性及其生理作用尚不清楚。我们通过两个连续的单克隆抗体亲和层析循环，从由仙台病毒诱导的外周血白细胞来源的人白细胞干扰素制剂中纯化出了IFN-ω1。通过反相高效液相色谱法测定，所得蛋白质的纯度至少为95%，在十二烷基硫酸钠 - 凝胶电泳中显示分子量为24,500（理论分子量为19,984）。氨基酸序列分析表明，只有约40%的分子具有基于与IFN-α序列相似性预期的NH2末端，而其他分子则含有另外两个氨基酸。这种差异可能是由于信号肽酶对前体蛋白的可变切割所致。未发现COOH末端异质性的证据。基本上所有的IFN-ω1分子都被糖基化；酶促去糖基化导致分子量降至20,500。使用几种植物凝集素的实验表明存在含有神经氨酸的双天线复杂寡糖。在色谱聚焦时观察到两个主要峰，等电点分别为8.1和8.5。在人细胞上测定的纯化IFN-ω1的特异性抗病毒活性被确定为2.7×10(8) IU/mg，与其他人类I类干扰素相似；在牛和羊的细胞上也观察到了强抗病毒活性，但在马或鼠源细胞上未观察到。
