Eberth Alexander, Dvorsky Radovan, Becker Christian F W, Beste Andrea, Goody Roger S, Ahmadian Mohammad Reza
Department of Structural Biology, Max-Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, D-44227 Dortmund, Germany.
Biol Chem. 2005 Nov;386(11):1105-14. doi: 10.1515/BC.2005.127.
The conversion of guanosine triphosphate (GTP) to guanosine diphosphate (GDP) and inorganic phosphate (Pi) by guanine nucleotide-binding proteins (GNBPs) is a fundamental enzyme reaction in living cells that acts as an important timer in a variety of biological processes. This reaction is intrinsically slow but can be stimulated by GTPase-activating proteins (GAPs) by several orders of magnitude. In the present study, we synthesized and characterized a new fluorescent nucleotide, 2'(3')-O-(N-ethylcarbamoyl-(5''-carboxytetramethylrhodamine) amide)-GTP, or tamraGTP, which is sensitive towards conformational changes of certain GNBPs induced by GTP hydrolysis. Unlike other fluorescent nucleotides, tamra-GTP allows real-time monitoring of the kinetics of the intrinsic and GAP-catalyzed GTP hydrolysis reactions of small GNBPs from the Rho family.
鸟嘌呤核苷酸结合蛋白（GNBPs）将三磷酸鸟苷（GTP）转化为二磷酸鸟苷（GDP）和无机磷酸（Pi）是活细胞中的一种基本酶促反应，在多种生物过程中起着重要的计时作用。该反应本质上较慢，但可被GTP酶激活蛋白（GAPs）刺激加快几个数量级。在本研究中，我们合成并表征了一种新的荧光核苷酸，2'（3'）-O-（N-乙基氨基甲酰-（5''-羧基四甲基罗丹明）酰胺）-GTP，即tamraGTP，它对GTP水解诱导的某些GNBPs的构象变化敏感。与其他荧光核苷酸不同，tamra-GTP能够实时监测来自Rho家族的小GNBPs的内在和GAP催化的GTP水解反应的动力学。
