文章基本信息

标题：Major proteinase movement upon stable serpin–proteinase complex formation
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作者：Efstratios Stratikos ; Peter G. W. Gettins
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1997
卷号：94
期号：2
页码：453-458
DOI：10.1073/pnas.94.2.453
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：To determine whether formation of the stable complex between a serpin and a target proteinase involves a major translocation of the proteinase from its initial position in the noncovalent Michaelis complex, we have used fluorescence resonance energy transfer to measure the separation between fluorescein attached to a single cysteine on the serpin and tetramethylrhodamine conjugated to the proteinase. The interfluorophore separation was determined for the noncovalent Michaelis-like complex formed between 1-proteinase inhibitor (Pittsburgh variant) and anhydrotrypsin and for the stable complex between the same serpin and trypsin. A difference in separation between the two fluorophores of {approx}21 A was found for the two types of complex. This demonstrates a major movement of the proteinase in going from the initial noncovalent encounter complex to the kinetically stable complex. The change in interfluorophore separation is most readily understood in terms of movement of the proteinase from the reactive center end of the serpin toward the distal end, as the covalently attached reactive center loop inserts into {beta}-sheet A of the serpin.
关键词：α₁-proteinase inhibitor Pittsburgh ; proteinase inhibition ; fluorescence resonance energy transfer