Table 2.

Peptides that block SARS-CoV-2 S protein interaction with cellular ACE2

Peptide	Amino acid sequence	Origin	Possible use	Assessment of neutralization activity against SARS-CoV-2	References
SBP1	IEEQAKTFLDKFNHEAEDLFYQS	N-terminal fragment of α1-helix of ACE2	blocker of S protein (RBD) interaction with ACE2	in vitro neutralizing activity was not tested, interaction with SARS-CoV-2 RBD in an artificial system was observed at a concentration of 45 nM	[84]
P8	SALEEQLKTFLDKFMHELEDLLYQLAL-NH2	N-terminal fragment of α1-helix of ACE2	blocker of S protein (RBD) interaction with ACE2	high neutralizing activity in vitro (100% efficiency at a concentration of 1 µM)	[85]
P9	SALEEQYKTFLDKFM HELEDLLYQLSL-NH2	N-terminal fragment of α1-helix of ACE2	blocker of S protein (RBD) interaction with ACE2	high neutralizing activity in vitro (100% efficiency at a concentration of 1 µM)	[85]
P10	SALEEQYKTFLDKFMHELEDLLYQLAL-NH2	N-terminal fragment of α1-helix of ACE2	blocker of S protein (RBD) interaction with ACE2	high neutralizing activity in vitro (100% efficiency at a concentration of 1 µM)	[85]
8	IEEQAKTFLDKFNHER8EDLFYQS5	N-terminal fragment of α1-helix of ACE2	blocker of S protein (RBD) interaction with ACE2	absence of neutralizing activity in vitro (at a concentration of 0.1-1 mM)	[88]
G-link	IEEQAKTFLDKFNHEAEDLFYQSS-G-LGKGDFR	N-terminal fragment of α1-helix of ACE2	blocker of S protein (RBD) interaction with ACE2	absence of neutralizing activity in vitro (at a concentration of 0.1-1 mM)	[88]
G-link stapled	IR8EQAKTFS5DKFNHEAEDLFYQSS-G-LGKGDFR	N-terminal fragment of α1-helix of ACE2	blocker of S protein (RBD) interaction with ACE2	absence of neutralizing activity in vitro (at a concentration of 0.1-1 mM)	[88]
NYBSP-1	TIEEQAKT-X-LDK-X-NHEAEDLFYQ-X-SLA-X-WN	N-terminal fragment of α1-helix of ACE2	blocker of S protein (RBD) interaction with ACE2	high neutralizing activity in a pseudovirus system; IC50, 4.1 ± 0.26 µM	[89]
NYBSP-4	TIEEQ-Z-KTFLDK-X-NHEAEDLFYQ-X-SLA-X-WN	N-terminal fragment of α1-helix of ACE2	blocker of S protein (RBD) interaction with ACE2	high neutralizing activity in a pseudovirus system; IC50, 1.97 ± 0.14 µM	[89]
X1	cEEQAKTFLDKFNHEAEDLFYk S---------------------------------------S DKWSAFLKEQSTIAQNleYPLQECI	two N-terminal α-helices of ACE2	blocker of S protein (RBD) interaction with ACE2	interaction with SARS-CoV-2 RBD in an artificial system (1-10 mM), absence of neutralizing activity in vitro	[90]
X2	IEEQAKTFLDKFNHQAEDLFYkCO(CH2)2S----S DKWSAFLKECSTIAQIYPLQEI	two N-terminal α-helices of ACE2	blocker of S protein (RBD) interaction with ACE2	interaction with SARS-CoV-2 RBD in an artificial system (1-10 mM), absence of neutralizing activity in vitro	[90]
P1	STIEEQAKTFLDKFNHEAEDLFYQSSLASWNY	N-terminal α1-helix of ACE2	blocker of S protein (RBD) interaction with ACE2	interaction with SARS-CoV-2 RBD in an artificial (minimal concentration: 0.46 µM)	[91]
P2	MSTIEEQAKTFLDKFNHEAEDLFYQSSLASWNYNTNITEENVQNMNNAGDKWSAFLKEQSTLAQMYPLQEIQNLTVKLQLQALQHHHHHH	two N-terminal α-helices of ACE2	blocker of S protein (RBD) interaction with ACE2	interaction with SARS-CoV-2 RBD in an artificial system (minimal concentration: 0.064 µM)	[91]
SAP1	TFLDKFNHEAEDLFYQ	N-terminal fragment of α1-helix of ACE2	blocker of S protein (RBD) interaction with ACE2	high neutralizing activity in a pseudovirus system; IC50, 2.39 ± 0.20 mM	[92]
SAP6	EDLFYQ	N-terminal fragment of α1-helix of ACE2	blocker of S protein (RBD) interaction with ACE2	high neutralizing activity in a pseudovirus system; IC50, 1.90 ± 0.14 mM	[92]
CPS4 dimer	NNYLWWMTEYHD	ACE2 receptor	anti-ACE2	blockade of SARS-CoV-2/RBD-ACE2 interaction; IC50, 31 nM	[93]