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Mca-APK(Dnp) ACE2 substrate

ACE2 (angiotensin-converting enzyme 2) is a metalloproteinase that requires a divalent cation positioned at the active site in order to perform catalysis. It has multiple physiological roles that revolve around its trivalent function: a negative regulator of the renin-angiotensin system, facilitator of amino acid transport, and the severe acute respiratory syndrome-coronavirus (SARS-CoV) and SARS-CoV-2 receptor. ACE2 has recently been identified as the SARS-CoV-2 receptor, the infective agent responsible for the coronavirus disease, providing a critical link between immunity, inflammation, ACE2, and cardiovascular disease. Although sharing a close evolutionary relationship with SARS-CoV, the receptor-binding domain of SARS-CoV-2 differs in several key amino acid residues, allowing for stronger binding affinity with the human ACE2 receptor, which may account for the greater pathogenicity of SARS-CoV-2. The loss of ACE2 function following binding by SARS-CoV-2 is driven by endocytosis and activation of proteolytic cleavage and processing. The ACE2 system is a critical protective pathway against heart failure with reduced and preserved ejection fraction including, myocardial infarction and hypertension, and against lung disease and diabetes mellitus. The control of gut dysbiosis and vascular permeability by ACE2 has emerged as an essential mechanism of pulmonary hypertension and diabetic cardiovascular complications. Mca-APK(Dnp) ACE2 substrate is a FRET peptide for measuring enzymatic activity in cells and tissues. It uses DNP as a quencher molecule to quench the fluorescence of methoxycoumarin (Mca). This interaction is abolished when the enzyme cleaves the proline-lysine residue and restore the fluorescence of Mca. This fluorogenic substrate offers more flexibility and higher throughput than the commonly used HPLC-separation-based methods.

Example protocol

AT A GLANCE

  1. Prepare test and blank samples (50 µL)
  2. Treat samples with inhibitors as desired
  3. Add Mca-APK(Dnp) ACE2 substrate working solution (50 µL)
  4. Incubate samples at 37 °C
  5. Measure fluorescence at Ex/Em = 320/430 nm (Cutoff = 420 nm) 

PREPARATION OF STOCK SOLUTIONS

Unless otherwise noted, all unused stock solutions should be divided into single-use aliquots and stored at -20 °C after preparation. Avoid repeated freeze-thaw cycles.

Mca-APK(Dnp) ACE2 substrate stock solution
Prepare 5-10 mM stock solution with appropriate amount of DMSO.
Note     Store solution at -20 °C in single use aliquots.
Note     Protect from light.

PREPARATION OF WORKING SOLUTION

Mca-APK(Dnp) ACE2 substrate working solution
Add 5 µL of Mca-APK(Dnp) ACE2 substrate stock solution (10 mM) in 1 mL of assay buffer to make Mca-APK(Dnp) ACE2 substrate working solution.
Note     The appropriate concentration for the substrate should be measured empirically.
Note     With the given formula, the final concentration is 50 µM.
Note     100 mM Tris-HCl containing 1 M NaCl, pH ∼ 7.5 can be used as an assay buffer. 600 µM of ZnCl2 can also be added to the buffer.

SAMPLE EXPERIMENTAL PROTOCOL

The following protocol can be used as guidelines.
  1. Prepare and add 50 µL of test samples and blank controls.
  2. Add 50 µL of Mca-APK(Dnp) ACE2 substrate working solution into the samples and blank samples.
  3. Incubate samples at 37 °C.
  4. Measure the fluorescence increase with a fluorescence plate reader at Ex/Em = 320/430 nm (Cutoff = 420 nm). 
For kinetic reading: Immediately start measuring fluorescence intensity continuously and record data every 5 minutes for 30-120 minutes.
For end-point reading: Incubate the reaction at a desired temperature for 30 to 120 minutes, protected from light. Then measure the fluorescence intensity

Spectrum

References

View all 50 references: Citation Explorer
Impact of sex and gender on COVID-19 outcomes in Europe.
Authors: Gebhard, Catherine and Regitz-Zagrosek, Vera and Neuhauser, Hannelore K and Morgan, Rosemary and Klein, Sabra L
Journal: Biology of sex differences (2020): 29
Protective role of ACE2 and its downregulation in SARS-CoV-2 infection leading to Macrophage Activation Syndrome: Therapeutic implications.
Authors: Banu, Nehla and Panikar, Sandeep Surendra and Leal, Lizbeth Riera and Leal, Annie Riera
Journal: Life sciences (2020): 117905
The SARS-CoV-2 receptor, ACE-2, is expressed on many different cell types: implications for ACE-inhibitor- and angiotensin II receptor blocker-based cardiovascular therapies.
Authors: Albini, Adriana and Di Guardo, Giovanni and Noonan, Douglas McClain and Lombardo, Michele
Journal: Internal and emergency medicine (2020): 759-766
Anti-Inflammatory Properties of Drugs Used to Control COVID-19 and their Effects on the Renin-Angiotensin System and Angiotensin-Converting Enzyme-2.
Authors: Gilzad-Kohan, Hamed and Jamali, Fakhreddin
Journal: Journal of pharmacy & pharmaceutical sciences : a publication of the Canadian Society for Pharmaceutical Sciences, Societe canad (2020): 259-277
Role of the renin-angiotensin system in kidney development and programming of adult blood pressure.
Authors: Almeida, Lucas F and Tofteng, Signe S and Madsen, Kirsten and Jensen, Boye L
Journal: Clinical science (London, England : 1979) (2020): 641-656
Page updated on November 23, 2024

Ordering information

Price
Unit size
1 mg
10 mg
Catalog Number
1355513556
Quantity
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Physical properties

Molecular weight

696.67

Solvent

DMSO

Spectral properties

Correction Factor (280 nm)

0.3

Excitation (nm)

322

Emission (nm)

381

Storage, safety and handling

H-phraseH303, H313, H333
Hazard symbolXN
Intended useResearch Use Only (RUO)
R-phraseR20, R21, R22

Storage

Freeze (< -15 °C); Minimize light exposure
UNSPSC12171501
Product Image
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Gallery Image 1
 ACE2 dose response was measure with  Mca-APK(Dnp) substrate.