Direct Competitive Kinetic Isotope Effect Measurement Using Quantitative Whole Molecule Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry.

Teodora Kljaic, Merritt A Scott, Veronica Guirguis, Michal Tyrlik, Andrew Liu, Myles B Poulin

Abstract read

In one paragraph

Article in Chembiochem : a European journal of chemical biology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it

0cells of the map it votes in

0citing papers in PubMed

–field-weighted citation impact

1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Teodora KljaicDepartment of Chemistry & Biochemistry, University of Maryland at College Park, College Park, Maryland, USA.

Merritt A ScottDepartment of Chemistry & Biochemistry, University of Maryland at College Park, College Park, Maryland, USA.

Veronica GuirguisDepartment of Chemistry & Biochemistry, University of Maryland at College Park, College Park, Maryland, USA.

Michal TyrlikDepartment of Chemistry & Biochemistry, University of Maryland at College Park, College Park, Maryland, USA.

Andrew LiuDepartment of Chemistry & Biochemistry, University of Maryland at College Park, College Park, Maryland, USA.

Myles B PoulinDepartment of Chemistry & Biochemistry, University of Maryland at College Park, College Park, Maryland, USA.ORCID https://orcid.org/0000-0002-3789-703X

Funding

National Science Foundation CHE1945162

6 · The paper itself

Abstract

Kinetic isotope effect (KIE) measurements are a powerful tool to interrogate the microscopic steps in enzyme catalyzed reactions and can provide detailed information about transition state structures. However, the application of KIE measurements to study enzymatic reactions is not widely applied due to the tedious and complex analytical workflows required to measure KIEs with sufficient precession. Here, we report a method for the direct measurement of competitive KIEs using a whole molecule matrix-assisted laser desorption ionization (MALDI) time-of-flight (TOF) mass spectrometry (MS). Using isotope labeled internal standard introduced when quenching the enzyme reaction at multiple time points enables the simultaneous measurement of both the relative heavy/light isotope ratio R and fractional conversion F relative to the internal standard for each sample as the reaction progresses. We applied this approach to measure both [1'-

Indexed as

beta-GalactosidaseLactoseSpectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationCarbon IsotopesEscherichia coliHydrolysisIsotope LabelingKineticsbeta-GalactosidaseCarbon IsotopesLactoseenzymologykinetic isotope effectmass spectrometrymatrix‐assisted laser desorption ionization time‐of‐flightβ‐galactosidase

Identifiers

PMID42340071

DOI10.1002/cbic.202500539

PMCPMC13292192

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.