Proceedings Of The National Academy Of Sciences | September 7, 2007
Hans H. Gorris, David M. Rissin and David R. Walt
Proceedings of the National Academy of Sciences
DOI: 10.1021/ja058425e
Abstract: Inhibition kinetics of single-β-galactosidase molecules with the slow-binding inhibitor D-galactal have been characterized by segregating individual enzyme molecules in an array of 50,000 ultra small reaction containers and observing substrate turnover changes with fluorescence microscopy. Inhibited and active states of β-galactosidase could be clearly distinguished, and the large array size provided very good statistics. With a pre-steady-state experiment, we demonstrated the stochastic character of inhibitor release, which obeys first-order kinetics. Under steady-state conditions, the quantitative detection of substrate turnover changes over long time periods revealed repeated inhibitor binding and release events, which are accompanied by conformational changes of the enzyme’s catalytic site. We proved that the rate constants of inhibitor release and binding derived from stochastic changes in the substrate turnover are consistent with bulk-reaction kinetics.
Related Posts
Neurology
Comparative Spatial Analyses of the Tumor Immune Landscape in Mouse Models of Glioblastoma Using the PhenoCode Discovery Mouse Neuro Panel and Customized Markers
Poster Background Developing effective therapies for glioblastoma (GBM) relies on robust preclinical animal models that enable detailed investigation of tumor biology, discovery of therapeutic targets, and evaluation of new treatment…
Oncology
Development of a Spatial Metabolic Map of Immunotherapy Sensitive and Resistant Cutaneous Skin Carcinoma
Poster Background Ultrahigh-Plex Single-cell Spatial Phenotyping has revealed valuable insights into the tumor immune microenvironment (TiME) for biomarker discovery and stratification of clinical responses. Metabolic reprogramming is a key hallmark…
Spatial Immunometabolic Profiling of Non-Small Cell Lung Cancer Reveals Distinct Immune Exclusion Patterns and Functional Niches
Analytical validation of a multiplex immunofluorescence 7-Biomarker Immunoprint® assay on the Akoya PhenoImager HT platform for stage I/II Melanoma
Neurology
Neurodegenerative biomarkers in different chambers of the eye relative to plasma: an agreement validation study
Alzheimer’s Research and Therapy | August 26, 2024 Sampani K, Ness S, Tuz-Zahra F, Aytan N, Spurlock EE, Alluri S, Chen X, Siegel NH, Alosco ML, Xia W, Tripodis Y,…
Neurology
Clinical validation of the LucentAD p-Tau 217 as a lab developed test (LDT) for clinical use
Poster The intersection of new therapeutic options for Alzheimer’s disease (AD), the emergence of accurate blood-based tests for AD, and the anticipated health system log jam for confirmatory diagnostic testing…
Neurology
Development of thresholds and a visualization tool for use of a blood test in routine clinical dementia practice
Alzheimer’s & Dementia | August 3, 2024 Verberk IMW, Jutte J, Kingma MY, Vigneswaran S, Gouda MMTEE, van Engelen MP, Alcolea D, Arranz J, Fortea J, Lleó A, Chevalier C,…
Neurology
Discovering novel plasma biomarkers for ischemic stroke: Lipidomic and metabolomic analyses in an aged mouse model
Journal of Lipid Research | August 2, 2024 Becktel DA, Frye JB, Le EH, Whitman SA, Schnellmann RG, Morrison HW, Doyle KP. J Lipid Res. 2024 https://doi.org/10.1016/j.jlr.2024.100614 Abstract Ischemic stroke…