Schaller J, Nick H, Rickli E E, Gillessen D, Lergier W, Studer R O
Eur J Biochem. 1982 Jul;125(2):251-7. doi: 10.1111/j.1432-1033.1982.tb06676.x.
Low-molecular-weight urokinase (molecular weight 33100) was separated by analytical and preparative isoelectric focusing into five major subforms with isoelectric points between 8.7 and 9.6. These subforms are very similar in molecular weight, specific activity, amino acid composition and content of amino sugar and their N-terminal sequence constellation is identical. Low-molecular-weight urokinase consists of two polypeptide chains connected by a single disulfide bridge. The N-terminal region of the heavy chain (calculated Mr 30700) exhibits homology within the first 46 residues analyzed, with the known primary structure of other serine proteases. The mini chain (Mr 2426), whose complete sequence was determined, consists of 21 residues which show homology with the primary structure of the C-terminal region of the plasmin heavy chain. Based on sequence data and homology criteria with serine proteases a single-chain urokinase precursor is postulated having a peptide bond constellation between heavy and light chain region compatible with the requirements for serine protease activation.
低分子量尿激酶（分子量33100）通过分析型和制备型等电聚焦分离为5种主要亚基形式，其等电点在8.7至9.6之间。这些亚基形式在分子量、比活性、氨基酸组成、氨基糖含量方面非常相似，并且它们的N端序列组成相同。低分子量尿激酶由两条通过单个二硫键连接的多肽链组成。重链（计算分子量为30700）的N端区域在分析的前46个残基内与其他丝氨酸蛋白酶的已知一级结构具有同源性。已确定其完整序列的小链（分子量2426）由21个残基组成，这些残基与纤溶酶重链C端区域的一级结构具有同源性。基于序列数据以及与丝氨酸蛋白酶的同源性标准，推测存在一种单链尿激酶前体，其重链和轻链区域之间的肽键组成符合丝氨酸蛋白酶激活的要求。
