A Peptidomimetic Fluorescent Probe to Detect the Trypsin β2 Subunit of the Human 20S Proteasome
Faculty of Chemistry, University of Gdansk, Ul. Wita Stwosza 63, 80-308 Gdansk, Poland
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Author to whom correspondence should be addressed.
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These authors contributed equally to this work.
Int. J. Mol. Sci. 2020, 21(7), 2396; https://doi.org/10.3390/ijms21072396
Received: 2 March 2020 / Revised: 25 March 2020 / Accepted: 29 March 2020 / Published: 31 March 2020
(This article belongs to the Special Issue Biocatalysis: Mechanisms of Proteolytic Enzymes)
This work describes the chemical synthesis, combinatorial selection, and enzymatic evaluation of peptidomimetic fluorescent substrates specific for the trypsin-like (β2) subunit of the 20S human proteasome. After deconvolution of a library comprising nearly 6000 compounds composed of peg substituted diaminopropionic acid DAPEG building blocks, the sequence ABZ–Dap(O2(Cbz))–Dap(GO1)–Dap(O2(Cbz))–Arg–ANB–NH2, where ABZ is 2-aminobenzoic acid, and ANB- 5 amino 2- nitro benzoic acid was selected. Its cleavage followed sigmoidal kinetics, characteristic for allosteric enzymes, with Km = 3.22 ± 0.02 μM, kcat = 245 s−1, and kcat/Km = 7.61 × 107 M−1 s−1. This process was practically halted when a selective inhibitor of the β2 subunit of the 20S human proteasome was supplemented to the reaction system. Titration of the substrate resulting in decreased amounts of proteasome 20S produced a linear signal up to 10−11 M. Using this substrate, we detected human proteasome 20S in human urine samples taken from the bladders of cancer patients. This observation could be useful for the noninvasive diagnosis of this severe disease.
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Keywords:
peptidomimetics; libraries; fluorogenic substrates; proteasome; bladder cancer
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MDPI and ACS Style
Wysocka, M.; Romanowska, A.; Gruba, N.; Michalska, M.; Giełdoń, A.; Lesner, A. A Peptidomimetic Fluorescent Probe to Detect the Trypsin β2 Subunit of the Human 20S Proteasome. Int. J. Mol. Sci. 2020, 21, 2396.
AMA Style
Wysocka M, Romanowska A, Gruba N, Michalska M, Giełdoń A, Lesner A. A Peptidomimetic Fluorescent Probe to Detect the Trypsin β2 Subunit of the Human 20S Proteasome. International Journal of Molecular Sciences. 2020; 21(7):2396.
Chicago/Turabian StyleWysocka, Magdalena; Romanowska, Anita; Gruba, Natalia; Michalska, Michalina; Giełdoń, Artur; Lesner, Adam. 2020. "A Peptidomimetic Fluorescent Probe to Detect the Trypsin β2 Subunit of the Human 20S Proteasome" Int. J. Mol. Sci. 21, no. 7: 2396.
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