Identification of critical determinants on ACE2 for SARS-CoV entry and development of a potent entry inhibitor

Abstract

Severe acute respiratory syndrome (SARS) is caused by a novel coronavirus, SARS-CoV. Virus entry into cells is mediated through interactions between spike (S) glycoprotein and angiotensin-converting enzyme 2 (ACE2). Alanine scanning mutagenesis analysis was performed to identify determinants on ACE2 critical for SARS-CoV infection. Results indicated that charged amino acids between residues 22 and 57 were important, K26 and D30, in particular. Peptides representing various regions of ACE2 critical for virus infection were chemically synthesized and evaluated for antiviral activity. Two peptides (a.a. 22-44 and 22-57) exhibited a modest antiviral activity with IC50 of about 50 microM and 6 microM, respectively. One peptide comprised of two discontinuous segments of ACE2 (a.a. 22-44 and 351-357) artificially linked together by glycine, exhibited a potent antiviral activity with IC50 of about 0.1 microM. This novel peptide is a promising candidate as a therapeutic agent against this deadly emerging pathogen.

Physiology of Kidney Renin

“…In addition, ACE2 is a well-described receptor for the severe acute respiratory syndrome coronavirus (SARS-CoV) and for the human coronavirus-NL63 (348,515). The SARSCoV infection can be attenuated by soluble ACE2 molecules, ACE2 antibodies, and the genetic deletion of ACE2 (304,472,515).…”

Identification of key amino acid residues required for horseshoe bat angiotensin-I converting enzyme 2 to function as a receptor for severe acute respiratory syndrome coronavirus

“…One of the more significant achievements was the identification of the angiotensin-I converting enzyme 2 (ACE2) as the cellular receptor for SARS-CoV . This discovery opened up new opportunities in the search for novel antiviral drugs as part of the overall countermeasure strategy to aid in the control of any future outbreaks (Han et al, 2006;Kuhn et al, 2007).In comparison, the progress in elucidating the origin of SARS-CoV was relatively slow and less straightforward. Although it was recognized very early during the outbreaks that SARS-CoV was most probably a virus of animal origin and that the virus entered the human population as a result of a spillover event(s), the exact reservoir species of the SARS-CoV and the path of the spillover event remain unknown Normile & Enserink, 2003;Wang & Eaton, 2007;Wang et al, 2006).…”

“…One of the more significant achievements was the identification of the angiotensin-I converting enzyme 2 (ACE2) as the cellular receptor for SARS-CoV . This discovery opened up new opportunities in the search for novel antiviral drugs as part of the overall countermeasure strategy to aid in the control of any future outbreaks (Han et al, 2006;Kuhn et al, 2007).…”

How Prepared Are We to Control Severe Acute Respiratory Syndrome in Future

“…Agents that target these steps have been identified and analyzed for their inhibitory effects on SARS-CoV entry. Classes of entry inhibitor include siRNA to spike protein gene (Qin et al, 2004), peptides or recombinant proteins derived from S protein (Ni et al, 2005;Sainz et al, 2006;Ujike et al, 2008;Struck et al, 2012) or ACE2 (Imai et al, 2005;Han et al, 2006), small molecules that bind S protein (Yi et al, 2004) and inhibitors of cellular protease (Simmons et al, 2005;Wang et al, 2007;Zhou et al, 2011). In addition, TNF-α Converting Enzyme (TACE) and lactoferrin bound to heparin sulfate proteoglycans have also been identified as targets for inhibition of viral entry (Haga et al, 2010;Lang et al, 2011).…”