“…In the second part of this experiment, the starting concentrations of the substrate were varied to calculate kinetic data for the enzyme reaction (Figure b). Using initial velocities, the K M value for the substrate neurotensin was calculated to be 520 μM, which lies in the range of comparable substrates found in the literature. , Note that for accurate determination of kinetic parameters by Lineweaver−Burk plot, more sampling points in the early phase of the reaction would be beneficial to cover a wider linear range. 3 Tryptic digest of neurotensin monitored in the matrix InAA−DMED.…”
Section: Resultsmentioning
confidence: 69%
“…Using initial velocities, the K M value for the substrate neurotensin was calculated to be 520 µM, which lies in the range of comparable substrates found in the literature. 44,45 Note that for accurate determination of kinetic parameters by Lineweaver-Burk plot, more sampling points in the early phase of the reaction would be beneficial to cover a wider linear range.…”
Ionic liquid matrixes (ILM) have been shown to allow very homogeneous sample preparations, facilitating relative quantifications using internal standards in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). In the present work, the ability to perform quantifications of peptides without using internal standards in these matrixes was investigated. Linear correlations between peptide amount and signal intensities could be observed when increased molar matrix-to-analyte ratios were applied. The dynamic range of linearity was approximately 1 order of magnitude. The method was applied successfully to monitor the time-dependent evolution of substrates and products in trypsin-catalyzed digests of single peptides and peptide mixtures. Thus, ionic liquid matrixes allow quantitative MALDI-MS without the need for internal standards, making the method a suitable tool for the fast screening of new enzymes or the search for substrates or inhibitors.
“…In the second part of this experiment, the starting concentrations of the substrate were varied to calculate kinetic data for the enzyme reaction (Figure b). Using initial velocities, the K M value for the substrate neurotensin was calculated to be 520 μM, which lies in the range of comparable substrates found in the literature. , Note that for accurate determination of kinetic parameters by Lineweaver−Burk plot, more sampling points in the early phase of the reaction would be beneficial to cover a wider linear range. 3 Tryptic digest of neurotensin monitored in the matrix InAA−DMED.…”
Section: Resultsmentioning
confidence: 69%
“…Using initial velocities, the K M value for the substrate neurotensin was calculated to be 520 µM, which lies in the range of comparable substrates found in the literature. 44,45 Note that for accurate determination of kinetic parameters by Lineweaver-Burk plot, more sampling points in the early phase of the reaction would be beneficial to cover a wider linear range.…”
Ionic liquid matrixes (ILM) have been shown to allow very homogeneous sample preparations, facilitating relative quantifications using internal standards in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). In the present work, the ability to perform quantifications of peptides without using internal standards in these matrixes was investigated. Linear correlations between peptide amount and signal intensities could be observed when increased molar matrix-to-analyte ratios were applied. The dynamic range of linearity was approximately 1 order of magnitude. The method was applied successfully to monitor the time-dependent evolution of substrates and products in trypsin-catalyzed digests of single peptides and peptide mixtures. Thus, ionic liquid matrixes allow quantitative MALDI-MS without the need for internal standards, making the method a suitable tool for the fast screening of new enzymes or the search for substrates or inhibitors.
“…The method for solution conductance monitoring was originally developed for determining chemical reaction rates and only recently it has been applied to reactions catalysed by enzymes [6][7][8], namely, ure ase [6,9], proteases |8], oxidases [10], amidases and peptidases [11 ].…”
Section: Con Ductance Measurements Usually Involve the Resistance Detmentioning
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
