This invention relates to enzyme-sensitive biosensors and methods and kits using the same. Specifically, the invention relates to methods, systems and kits for the detection of enzymes using the chemical shift observed in an isotope complexed to the biosensor resulting from a change in the biosensor as the result of the enzyme's activity.
This invention relates to enzyme-sensitive biosensors and methods and kits using the same. Specifically, the invention relates to methods, systems and kits for the detection of enzymes using the chemical shift observed in an isotope complexed to the biosensor resulting from a change in the biosensor as the result of the enzyme's activity.
Designing <sup>129</sup>Xe NMR Biosensors for Matrix Metalloproteinase Detection
作者:Qian Wei、Garry K. Seward、P. Aru Hill、Brian Patton、Ivan E. Dimitrov、Nicholas N. Kuzma、Ivan J. Dmochowski
DOI:10.1021/ja0640501
日期:2006.10.1
Xenon-129 biosensors offer an attractive alternative to conventional MRI contrast agents due to the chemical shift sensitivity and large nuclear magnetic signal of hyperpolarized Xe-129. Here, we report the first enzyme-responsive Xe-129 NMR biosensor. This compound was synthesized in 13 steps by attaching the consensus peptide substrate for matrix metalloproteinase-7 (MMP-7), an enzyme that is upregulated in many cancers, to the xenon-binding organic cage, cryptophane-A. The final coupling step was achieved on solid support in 80-92% yield via a copper (I)-catalyzed [3+2] cycloaddition. In vitro enzymatic cleavage assays were monitored by HPLC and fluorescence spectroscopy. The biosensor was determined to be an excellent substrate for MMP-7 (K-M = 43 mu M, V-max = 1.3 x 10(-8) M s(-1), k(cat)/K-M = 7200 M-1 s(-1)). Enzymatic cleavage of the tryptophan-containing peptide led to a dramatic decrease in Trp fluorescence, lambda(max) = 358 nm. Stern-Volmer analysis gave an association constant of 9000 +/- 1000 M-1 at 298 K between the cage and Trp-containing hexapeptide under enzymatic assay conditions. Most promisingly, Xe-129 NMR spectroscopy distinguished between the intact and cleaved biosensors with a 0.5 ppm difference in chemical shift. This difference most likely reflected a change in the electrostatic environment of Xe-129, caused by the cleavage of three positively charged residues from the C-terminus. This work provides guidelines for the design and application of new enzyme-responsive Xe-129 NMR biosensors.
US8470587B2
申请人:——
公开号:US8470587B2
公开(公告)日:2013-06-25
[EN] 129XE BIOSENSORS AND THEIR USE<br/>[FR] BIOCAPTEURS 129XE ET LEUR UTILISATION
申请人:UNIV PENNSYLVANIA
公开号:WO2008027162A2
公开(公告)日:2008-03-06
[EN] This invention relates to enzyme-sensitive biosensors and methods and kits using the same. Specifically, the invention relates to methods, systems and kits for the detection of enzymes using the chemical shift observed in an isotope complexed to the biosensor resulting from a change in the biosensor as the result of the enzyme's activity. [FR] L'invention concerne des biocapteurs sensibles aux enzymes, des procédés et des ensembles employant ces biocapteurs. L'invention concerne plus particulièrement des procédés, des systèmes et des ensembles de détection d'enzymes au moyen du décalage chimique observé dans un isotope complexé au biocapteur résultant d'un changement dans le biocapteur en résultat de l'activité de l'enzyme.