| Name: | Recombinant ACE2 SARS-CoV1 and SARS-CoV2 binding domain |
| HGNC Name: | ACE2 |
| RRID: | Pending |
| Format: | Supplied as 1mg/mL in 6M urea, 10mM phosphate buffer pH=7.5 |
| Applications: | Antibody generation, ELISA |
| Storage: | Stable at 4°C for several months. For longer term store at -20°C, minimize freeze/thaw cycles |
| Uniprot: | Q9BYF1 |
SDS-PAGE gel of recombinant human ACE2 virus binding region. Lane 1 shows protein molecular weight standards of apparent size indicated in kiloDaltons. Lanes 2 and 3 are 5.6μg and 2.8μg BSA and 4 and 5 are the ACE2 construct running at an apparent molecular weight about 70kDa, somewhat higher than the 63kDa predicted from the amino acid sequence. This discrepancy is likely due to the highly acidic nature of the protein. The protein was expressed in
Recombinant ACE2 SARS-CoV2 Binding Domain
$300.00 – $2,000.00
There has been an enormous amount of interest in the novel virus SARS-CoV-2 for very obvious reasons. It is a corona virus, a member of a large family of spherical viruses with prominent spikes which give them the appearance of a cartoon sun, which is why they are called corona viruses. The SARS-CoV-2 virus was first identified in Wuhan, China, at the end of 2019 and almost certainly originated from bats, possibly infecting humans after having passed through another animal host (1,2). The virus transmits very readily and has a significant mortality with particular risk to individuals with comorbidities such as diabetes, hypertension, immune compromise and heart problems. While no age group seems to be safe the majority of patients who have serious symptoms or succumb are of advanced age. Much research has shown that a part of the “spike” or S protein on the surface of the virus has a high affinity binding site for angiotensin converting enzyme 2 (ACE2) a protein on the surface of human cells in the lung epitheliun and other tissues (3). This specific binding is required for internalization of the virus and is the first step in viral infection. Accordingly antibodies or other reagents which bind to the ACE2/SARS-CoV-2 interaction site may interfere with viral internalization and hence infection. Recent cryoEM studies have characterized the exact interface (4). We have therefore made two recombinant constructs, this one including the segment of ACE2 which binds the SARS-CoV-2 spike protein, and also PROT-R-SARS-CoV2-bd, containing the region of the SARS-CoV-2 spike protein which binds to ACE2.
The sequence below is that of our recombinant construct of the ACE2 extracellular domain which includes the entire region which interacts with both SARS-CoV1 and SARS-CoV2. The specific binding of both SARS viruses to ACE2 is essential for viral internalization and infection. We designed this construct based on amino acids 1-500 in the S-protein sequence in BAB40370.1. This is a defined globular domain recently shown to include all of the amino acids necessary for ACE2 binding (4). Human ACE2 is 805 amino acids long so this construct is missing the C-terminal 305 amino acids, which at 741-763, includes a membrane spanning domain. The construct lacks this region as inclusion would likely have made the molecule difficult to express. The construct was expressed in and purified from E. coli and includes an N-terminal His-tag and other vector derived sequence shown underlined below. Amino acids printed in bold below are those which have been shown to interact with the SARS-CoV2 binding domain, data from Yan et al. (4). The highlighted residues are Q24, D30, H34, Y31, Q32, M82 and R357.
MHHHHHHSSG LVPRGSGMKE TAAAKFERQH MDSPDLGTDD DDKAMADIGS EFMSSSSWLL 60
LSLVAVTAAQ STIEEQAKTF LDKFNHEAED LFYQSSLASW NYNTNITEEN VQNMNNAGDK 120
WSAFLKEQST LAQMYPLQEI QNLTVKLQLQ ALQQNGSSVL SEDKSKRLNT ILNTMSTIYS 180
TGKVCNPDNP QECLLLEPGL NEIMANSLDY NERLWAWESW RSEVGKQLRP LYEEYVVLKN 240
EMARANHYED YGDYWRGDYE VNGVDGYDYS RGQLIEDVEH TFEEIKPLYE HLHAYVRAKL 300
MNAYPSYISP IGCLPAHLLG DMWGRFWTNL YSLTVPFGQK PNIDVTDAMV DQAWDAQRIF 360
KEAEKFFVSV GLPNMTQGFW ENSMLTDPGN VQKAVCHPTA WDLGKGDFRI LMCTKVTMDD 420
FLTAHHEMGH IQYDMAYAAQ PFLLRNGANE GFHEAVGEIM SLSAATPKHL KSIGLLSPDF 480
QEDNETEINF LLKQALTIVG TLPFTYMLEK WRWMVFKGEI PKDQWMKKWW EMKREIVGVV 540
EPVPHDETYC DP 552
Number of amino acids: 552
Molecular weight: 63268.30
Theoretical pI: 4.94
Amino acid composition:
Ala (A) 38 6.9%
Arg (R) 16 2.9%
Asn (N) 30 5.4%
Asp (D) 35 6.3%
Cys (C) 6 1.1%
Gln (Q) 26 4.7%
Glu (E) 44 8.0%
Gly (G) 32 5.8%
His (H) 20 3.6%
Ile (I) 21 3.8%
Leu (L) 53 9.6%
Lys (K) 30 5.4%
Met (M) 24 4.3%
Phe (F) 21 3.8%
Pro (P) 24 4.3%
Ser (S) 35 6.3%
Thr (T) 29 5.3%
Trp (W) 17 3.1%
Tyr (Y) 22 4.0%
Val (V) 29 5.3%
Total number of negatively charged residues (Asp + Glu): 79
Total number of positively charged residues (Arg + Lys): 46
Ext. coefficient 126655
Abs 0.1% (=1 g/l) 2.002, assuming all pairs of Cys residues form cystines
Ext. coefficient 126280
Abs 0.1% (=1 g/l) 1.996, assuming all Cys residues are reduced
1. Wu, F et al. A new coronavirus associated with human respiratory disease in China. Nature doi:10.1038/s41586-020-2008-3.2020 579:265-269 (2020).
2. Ren, L-L et al. Identification of a novel coronavirus causing severe pneumonia in human: a descriptive study. Chin Med J (Engl) doi:10.1097/CM9.0000000000000722 133:1015-24 (2020).
3. Walls, A C et al. Structure, Function, and Antigenicity of the SARS-CoV-2 Spike Glycoprotein. Cell doi: 10.1016/j.cell.2020.02.058 180:1-12 (2020)
4. Yan, R et al. Structural basis for the recognition of SARS-CoV-2 by full-length human ACE2. Science doi:10.1126/science.abb2762 367:1444–8 (2020).
