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COVID-19 Research Tools

ACE2 Activity Assay Kit, Inhibitors & related products COVID-19 Research Tools

AnaSpec is committed to helping the global scientific community in their research and development endeavors to mitigate the COVID-19 pandemic by finding diagnostic and therapeutic solutions. Our peptide, fluorescent dye, and assay technologies can be combined to produce customized solutions or browse through our catalog products such as the ACE2 protease activity assay kit. With over 25 years of experience in serving the life science industry, we are ready to provide you with high quality, consistency, and safety.

ACE2 for COVID-19 therapeutic research and development

Cited in high impact journals, AnaSpec's SensoLyte® 390 ACE2 Activity Assay Kit provides a convenient assay for high throughput screening of ACE2 enzyme inhibitors and inducers that can have an impact on Coronavirus pathologic mechanisms.

The FRET assay uses a Mc-Ala/Dnp peptide to detect the activity of sub-nanogram level of ACE2

Optimized Performance to detect ACE2 activity
HTS compatible
Assured Reliability with detailed protocol

The angiotensin-converting enzyme2 (ACE2) is a carboxypeptidase best known for cleaving several peptides within the renin–angiotensin system and other substrates, such as apelin. In addition to its role in the regulation of hypertension, ACE2 is a functional receptor for coronavirus that causes severe acute respiratory syndrome (SARS) (1).

A recent study by Battle D et al (2020) has shown that a soluble form of ACE2 may act as a competitive inhibitor of SARS-CoV-2 and other coronaviruses by preventing the binding of the viral particle to the membrane-bound full-length form. Hence, the soluble form of ACE2 (having higher binding affinity to SARS-CoV-2 than SARS-CoV) could serve as a potentially novel therapeutic target to limit infection caused by SARS-CoV-2 (COVID-19).

Specifically, the extracellular domain of ACE2 has been demonstrated as a receptor for the spike (S) protein of SARS-CoV , and recently, for the SARS-CoV-2 or COVID-19 [2]. The spike (S) protein of Coronaviruses binds to membrane bound ACE2 receptor on host cells, thereby promoting viral entry [3]. ACE2, thus represents a potential therapeutic target for the SARS-CoV-2.

Figure 1. shows a schematic for ACE2 forms impacting viral entry into host cells.

ACE2 substrate and inhibitor

Product Name
Catalog #
ACE2 Substrate


DX 600, ACE2 Inhibitor

A study by Xiao and Burns (2017)*, has used ACE2 substrate from AnaSpec to measure the activity of ACE2 in biological fluids. The hydrolysis of an intramolecularly quenched fluorogenic ACE2 substrate, in the absence or presence of the ACE2 inhibitors MLN-4760 or DX600 formed the principle of their assay. Such type of assays can provide information about the functional role of ACE2 in biological fluids with respect to coronaviral fusion and replication.

Check out other citations of the ACE2 activity assay kit.

Figure 2. ACE inhibitor (DX600) inhibition of ACE2 activity measured with SensoLyte® 390 ACE2 Activity Assay Kit.

Cathepsin & Furin Activity Assay Kits

Certain viruses including the Coronaviruses depend on cathepsins (L & B) for entry into their target cells. The viral glycoproteins undergo protease cleavage, rendering them active for fusion with the host cell membrane. Peptides derived from the viral glycoproteins containing cathepsin cleavage sites have been used in high-throughput screening assays [4, Elshabrawy HA, et al, 2014*]. Such assays can help identify and screen for inhibitors that can prevent cathepsin cleavage of viral glycoproteins and disrupt viral fusion. Other cathepsin assay kits
It has been shown that MERS-CoV contains a furin cleavage site just upstream of the fusion peptide. The spike protein of some coronaviruses are cleaved at the S1/S2 boundary by furin(-like) proteases during transport of the newly assembled virions through the secretory pathway [5]. Hence, screening for furin inhibitors observed with furin-dependent viral replication may present as a potential target for drug design. Read more

Product Name
Catalog #
SensoLyte® Rh110 Furin Activity Assay Kit *Fluorimetric*


SensoLyte ® 520 Cathepsin B Assay Kit *Fluorimetric*


SensoLyte ® 440 Cathepsin B Assay Kit *Fluorimetric*
SensoLyte ® Rh110 Cathepsin L Assay Kit *Fluorimetric*


SensoLyte ® 520 Cathepsin L Assay Kit *Fluorimetric*



Peptides play various roles in the Coronavirus physiology. For example, certain peptides can serve as substrates for the proteolytic machinery of the viral fusion system or have inhibitory roles in viral autophagy.

Catalog Peptides

Product Name
Catalog #
96-well Overlapping Peptide Library (Spike glycoprotein from SARS-CoV-2) New
ACE2 Substrate
DX 600, ACE2 Inhibitor
Generic 3CLpro FRET peptide substrate New
pro-NPY peptide (34-43), human New
Spike protein (S1/S2) SARS-CoV-2 substrate New
Spike protein (S2) SARS-CoV-2 substrate New


Tat-Beclin-1, scrambled


It has been shown that the Coronavirus interacts differentially with components of the autophagic pathway either by using autophagy components for virus replication or for the attenuation of autophagy. As such peptides like TAT-Beclin 1 are being identified as molecules that can reduce replication of Coronaviruses (Eg.MERS-CoV) [6, Glassen C, et al. 2019*].

Custom Services

AnaSpec's expert and high-quality custom synthesis services can provide critical peptide domains/regions or substrates needed to understand coronaviral fusion mechanisms.

Synthesis of peptides such as the Heptad Repeat (HR) regions, which are characteristic of the viral spike proteins [7] could be beneficial in the development of novel therapeutic agents against COVID-19.
A peptide substrate custom synthesized by AnaSpec was used to measure the enzymatic activity of 3CLpro in the context of a coronaviral replication mechanism. (Tomar S, et al. 2015*).

Dye reagents/Substrates for studying expression in live cells

Product Name
Catalog #


SensoLyte ® FDG β-Galactosidase Assay Kit *Fluorimetric*


Fluorescein di(β-D-galactopyranoside) (FDG) is a fluorogenic substrate for β-galactosidase widely used to detect β-galactosidase expression in live cells. In a study by (5, Burkard C et al, 2014*), a novel and versatile assay was developed to enable distinctive analysis of the viral penetration/fusion process, as well as binding and internalization of viral particles in a replication-independent manner. Specifically, FDG substrate obtained from AnaSpec was used to

  • determine beta-galactosidase activity in a viral-cell fusion assay (steps included, virus binding to target cells - cells harvesting – FDG addition to enable uptake – FACS analysis to measure beta-galactosidase activity - Fusion-dependent β-galactosidase activity-driven fluorescein production in cells was visualized by fluorescence microscopy).

  • examine the effect of a drug treatment upon FDG uptake. (steps included; cells transfected with plasmids encoding mutant beta-gal – FDG addition to enable uptake - β-galactosidase activity determined using FACS by the production of fluorescein).

Underlying Disease Research Products

Diabetes research Cardiovascular disease research

Assays & Peptides

Renin Assays & related products
Thrombin Assays

*Featured Citations

  • Xiao F, Burns K.D. (2017) Measurement of Angiotensin Converting Enzyme 2 Activity in Biological Fluid (ACE2). In: Touyz R., Schiffrin E. (eds) Hypertension. Methods in Molecular Biology, vol 1527. Humana Press, New York, NY.
  • Elshabrawy HA, Fan J, Haddad CS, et al. Identification of a broad-spectrum antiviral small molecule against severe acute respiratory syndrome coronavirus and Ebola, Hendra, and Nipah viruses by using a novel high-throughput screening assay. J Virol. 2014;88(8):4353–4365.
  • Gassen NC, Niemeyer D, Muth D, Corman VM, Martinelli S, Gassen A, Hafner K, Papies J, Mösbauer K, Zellner A, Zannas AS. SKP2 attenuates autophagy through Beclin1-ubiquitination and its inhibition reduces MERS-Coronavirus infection. Nature Communications. 2019 Dec 18;10(1):1-6.
  • Tomar S, Johnston ML, John SE, Osswald HL, Nyalapatla PR, Paul LN, Ghosh AK, Denison MR, Mesecar AD. Ligand-induced Dimerization of Middle East Respiratory Syndrome (MERS) Coronavirus nsp5 Protease (3CLpro) IMPLICATIONS FOR nsp5 REGULATION AND THE DEVELOPMENT OF ANTIVIRALS. Journal of Biological Chemistry. 2015 Aug 7;290(32):19403-22.
  • Burkard C, Bloyet LM, Wicht O, et al. Dissecting virus entry: replication-independent analysis of virus binding, internalization, and penetration using minimal complementation of β-galactosidase. PLoS One. 2014;9(7):e101762.


  1. Li, W. et al. (2003) Nature 426, 450.
  2. Lu R., et al. (2020) Lancet 395, 565–574
  3. Du, L., et al. (2009) Nat. Rev. Microbiol 7, 226–236
  4. Elshabrawy HA, et al. (2014). Journal of Virology. 88(8), 4353-65.
  5. Burkard C, et al. (2014). PLoS One. 2014; 9(7):e101762.
  6. Gassen NC, et al. (2020) Nature Commun, 10(1), 1-6.
  7. Xia et al. (2019). Viruses. 11(1): 56.
  8. Batlle, D, et al (2020) Clin Sci 134(5), 543-545.

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