Recognition of different nucleotidyl-derivatives as substrates of reactions catalyzed by various HIT-proteins
作者:Andrzej Guranowski、Anna Maria Wojdyła、Jarosław Zimny、Anna Wypijewska、Joanna Kowalska、Maciej Łukaszewicz、Jacek Jemielity、Edward Darżynkiewicz、Agata Jagiełło、Paweł Bieganowski
DOI:10.1039/b9nj00660e
日期:——
Proteins that have a histidine triad in their active sites belong to the HIT-protein superfamily. They are ubiquitous, are involved in the metabolism of different nucleotides and catalyze their hydrolysis and/or phosphorolysis liberating either the corresponding 5′-NMP or 5′-NDP, respectively. We studied substrate specificity of nine recombinant HIT-proteins with adenosine 5′-phosphosulfate (1), adenosine 5′-phosphoramidate (2), adenosine 5′-phosphorothioate (3), adenosine 5′-phosphorofluoride (4), diadenosine 5′,5′′′-P1,P3-triphosphate (5), di(7-methylguanosine) 5′,5′′′-P1,P3-triphosphate (6) and adenosine 5′-hypophosphate (7). Preferences for the recognition of these compounds as substrates by individual proteins differed. All the proteins hydrolyzed (1) but the Arabidopsis thaliana Hint1 did it very slowly. None of the proteins cleaved (7). Only A. thaliana Hint1 and Escherichia coli HinT hydrolyzed (3). Three proteins known as dinucleoside triphosphatases, human and A. thaliana Fhit-proteins and Trypanosoma brucei HIT-45, cleaved (1), (2), (4), (5) and (6). Caenorhabditis elegans decapping protein DcpS degraded (1), (5), (6) and poorly (4). A. thaliana aprataxin-like protein and Hint4 hydrolyzed only (1), (2) and (4), in that order of efficiency. Velocities of those reactions and some Km values were determined. Applicability of this study to the metabolism of certain nucleotidyl-derivatives is discussed.
活性位点具有组氨酸三联体的蛋白质属于 HIT 蛋白质超家族。它们无处不在,参与不同核苷酸的代谢并催化它们的水解和/或磷酸解,分别释放相应的 5'-NMP 或 5'-NDP。我们研究了九种重组 HIT 蛋白的底物特异性,其中包括腺苷 5'-磷酸硫酸酯 (1)、腺苷 5'-氨基磷酸酯 (2)、腺苷 5'-硫代磷酸酯 (3)、腺苷 5'-氟化磷 (4)、二腺苷 5' ,5'''-P1,P3-三磷酸 (5)、二(7-甲基鸟苷) 5',5'''-P1,P3-三磷酸 (6) 和腺苷 5'-连二磷酸 (7)。各个蛋白质对这些化合物作为底物的识别偏好不同。所有蛋白质都会水解 (1),但拟南芥 Hint1 的水解速度非常缓慢。没有蛋白质被裂解 (7)。仅拟南芥 Hint1 和大肠杆菌 HinT 会水解 (3)。被称为二核苷三磷酸酶、人类和拟南芥 Fhit 蛋白以及布氏锥虫 HIT-45 的三种蛋白质被切割 (1)、(2)、(4)、(5) 和 (6)。秀丽隐杆线虫脱帽蛋白 DcpS 降解 (1)、(5)、(6) 和较差 (4)。拟南芥 aprataxin 样蛋白和 Hint4 按效率顺序仅水解 (1)、(2) 和 (4)。确定了这些反应的速度和一些 Km 值。讨论了本研究对某些核苷酸衍生物代谢的适用性。