Corti A, D'Ambrosio F, Marino M, Merli S, Cassani G
DIBIT, San Raffaele H Scientific Institute, Milan, Italy.
Eur Cytokine Netw. 1995 Jan-Feb;6(1):29-35.
Human urine is known to contain a 30 kDa soluble form of the p75-TNF receptor (sTNF-R2). In this work we have purified sTNF-R2 from the urine of normal subjects and further characterized its structure and activity. sTNF-R2 was resolved by reducing SDS-PAGE in a major band of 30 kDa, similar in size to the previously described urinary sTNFR2, and in a minor band of 45 kDa. "Western" blotting analysis with anti-TNF-R1 and anti-TNF-R2 antibodies showed that both bands were immunologically related to the membrane TNF-R2. Glycosylation studies indicated that the 30 kDa is N-glycosylated while the 45 kDa form is N- and O-glycosylated, and suggested that both forms contain terminally linked sialic acid that is differentially recognized by lectins. These results indicate that human urine contains, besides the 30 kDa form, a new form of 45 kDa characterized by different glycosylation type and degree.
已知人类尿液中含有一种分子量为30 kDa的可溶性p75肿瘤坏死因子受体（sTNF-R2）。在本研究中，我们从正常受试者的尿液中纯化了sTNF-R2，并进一步对其结构和活性进行了表征。通过还原型SDS-PAGE分析，sTNF-R2在30 kDa的主要条带中得以分离，其大小与先前描述的尿源性sTNFR2相似，同时还在45 kDa的次要条带中被分离出来。用抗TNF-R1和抗TNF-R2抗体进行的“Western”印迹分析表明，这两条带在免疫学上均与膜TNF-R2相关。糖基化研究表明，30 kDa的形式为N-糖基化，而45 kDa的形式为N-糖基化和O-糖基化，并且表明这两种形式均含有末端连接的唾液酸，而凝集素可对其进行差异性识别。这些结果表明，除了30 kDa的形式外，人类尿液中还含有一种新的45 kDa形式，其具有不同的糖基化类型和程度。
