Z-Phe-Arg-AMC . HCl

Z-Phe-Arg-AMC is a substrate for serine proteases, including cathepsins, kallikrein and plasmin.Absorption/emission of substrate = 330/390 nm.

The Km and Vmax of the recombinant CsCPL-m towards Z-Phe-Arg-AMC were determined to be 5.71 × 10-6 M and 0.6 µM/min, respectively, at 37 °C and pH 5.5. The recombinant CsCPL-m could degrade BSA and gelatine, but could not degrade human hemoglobin and human immunoglobulin G^[1].CatB and CatL activities in U2OS cell extracts were measured by fluorescent peptide conversion. The CatB/L-KO cells lacked CatB and CatL activity and were substantially resistant to EBOV GP-dependent entry^[2].When measured the total endopeptidase activity of cysteine cathepsins in cell-free supernatant from both MPS and non-MPS samples, using Z-Phe-Arg-AMC as a broad-spectrum substrate, and E-64 as titration reagent. A 2.5-fold decrease of active cathepsins was measured in all MPS types compared with controls^[3].

Plasma kallikrein activity was measured by the cleavage of the fluorometric substrate Z-Phe-Arg-AMC in plasma samples stimulated ex vivo with submaximal doses of dextran sulphate. Stimulated plasma kallikrein activity was significantly increased in both HAE-nl-C1INH and INHA subjects compared to non-swelling controls and histaminergic angioedema subjects. Using a threshold cut-off based on the normal controls^[4].The Sphenophorus levis is one of the main pests of sugarcane in Brazil.Higher gene expression levels of Sl-CathL-CS occur in the midgut of 30-day old larvae. Sl-CathL-CS presented no protease activity, but Sl-CathL-mutSC hydrolyzed Z-Phe-Arg-AMC and was inhibited by a cysteine protease inhibitor E-64 (Ki = 38.52±1.20 µM), but not by the serine protease inhibitor PMSF^[5].CPA in serum was determined with the spectrofluorometric technique using Z-Phe-Arg-AMC as a substrate. The highest CPA was found in breast cancer patients with a hereditary predisposition bearing BRCA1 gene mutations, and the lowest activity was found in patients who had a tumour surgically removed and before adjuvant therapy^[6].When evaluated the capacity of negatively charged glycosaminoglycans to modulate the activity of catS. Chondroitin 4-sulfate (C4-S) impaired the collagenolytic activity and inhibited the peptidase activity (Z-Phe-Arg-AMC) of catS at pH 5.5, obeying a mixed-type mechanism^[7].

References:
[1]: Ma C, Liang K, et,al. Identification and characteristics of a cathepsin L-like cysteine protease from Clonorchis sinensis. Parasitol Res. 2019 Mar;118(3):829-835. doi: 10.1007/s00436-019-06223-y. Epub 2019 Jan 28. PMID: 30689051.
[2]: Mittler E, Alkutkar T, et,al. Direct Intracellular Visualization of Ebola Virus-Receptor Interaction by In Situ Proximity Ligation. mBio. 2021 Jan 12;12(1):e03100-20. doi: 10.1128/mBio.03100-20. PMID: 33436438; PMCID: PMC7844541.
[3]: Chazeirat T, Denamur S, B et,al. The abnormal accumulation of heparan sulfate in patients with mucopolysaccharidosis prevents the elastolytic activity of cathepsin V. Carbohydr Polym. 2021 Feb 1;253:117261. doi: 10.1016/j.carbpol.2020.117261. Epub 2020 Oct 20. PMID: 33278943.
[4]: Lara-Marquez ML, Christiansen SC, et,al. Threshold-stimulated kallikrein activity distinguishes bradykinin- from histamine-mediated angioedema. Clin Exp Allergy. 2018 Nov;48(11):1429-1438. doi: 10.1111/cea.13219. Epub 2018 Aug 21. PMID: 29957871.
[5]: Shibao PYT, Ferro M, et,al. Identification and Functional Analysis of a Pseudo-Cysteine Protease from the Midgut Transcriptome of Sphenophorus levis. Int J Mol Sci. 2021 Oct 25;22(21):11476. doi: 10.3390/ijms222111476. PMID: 34768909; PMCID: PMC8583781.
[6]: Kilar E, Siewi¨½ski M, et,al. Differences in cysteine peptidases-like activity in sera of patients with breast cancer. Cancer Biomark. 2020;27(3):335-341. doi: 10.3233/CBM-190327. PMID: 31683457.
[7]: Sage J, MallÈvre F, et,al. Binding of chondroitin 4-sulfate to cathepsin S regulates its enzymatic activity. Biochemistry. 2013 Sep 17;52(37):6487-98. doi: 10.1021/bi400925g. Epub 2013 Sep 4. PMID: 23968158.