Nikandrov V N, Vorobyova G V, Yankovskaya G S, Demidchik N V
Laboratory of Biochemistry, Byelorussian Research Institute of Epidemiology and Microbiology, Minsk.
Int J Biol Macromol. 1992 Aug;14(4):229-34. doi: 10.1016/s0141-8130(05)80033-9.
Human, rabbit and bovine plasminogens, having different sensitivity to streptokinase-activating action, differ, according to spectrophotometric titration, tryptophan fluorescence and circular dichroism spectroscopy, in the state of tyrosine and tryptophan residues, and in secondary and tertiary structures. Human plasminogen-streptokinase equimolar complex formation (according to gel chromatography) is accompanied by a differential ultraviolet spectrum. Difference spectroscopy is a convenient and adequate means of studying the formation of the said complexes. Streptokinase-human plasminogen complex formation is not hindered by partial substitution of water (20%) with ethanol or dimethylsulphoxide or by addition of 0.001 M sodium dodecylsulphate. The complex is not formed in 6 M urea, in solution, at pH less than 2.0 or approximately 12.0-13.0, or with bovine plasminogen. Circular dichroism and tryptophan fluorescence spectral pattern changes during streptokinase-plasminogen complex formation enable us to conclude that streptokinase secondary and tertiary structures undergo certain rearrangements in the framework of the complex, while tryptophan-containing sites of the molecule are not drastically changed. The data obtained enable us to presuppose formation of streptokinase-rabbit plasminogen complexes which differ from human plasminogen complexes with streptokinase.
人、兔和牛的纤溶酶原对链激酶激活作用的敏感性不同，根据分光光度滴定、色氨酸荧光和圆二色光谱分析，它们在酪氨酸和色氨酸残基的状态以及二级和三级结构方面存在差异。人纤溶酶原与链激酶等摩尔复合物的形成（根据凝胶色谱法）伴随着差示紫外光谱。差示光谱法是研究上述复合物形成的一种方便且合适的手段。用乙醇或二甲基亚砜部分替代水（20%）或添加0.001 M十二烷基硫酸钠不会阻碍链激酶与人纤溶酶原复合物的形成。在6 M尿素中、pH小于2.0或约12.0 - 13.0的溶液中或与牛纤溶酶原一起时不会形成复合物。链激酶 - 纤溶酶原复合物形成过程中圆二色性和色氨酸荧光光谱模式的变化使我们能够得出结论，链激酶的二级和三级结构在复合物框架内发生了某些重排，而分子中含色氨酸的位点没有发生剧烈变化。所获得的数据使我们能够推测链激酶与兔纤溶酶原复合物的形成，这些复合物与链激酶与人纤溶酶原复合物不同。
