Table 4.

Summary of BLI virus–ligand cases discussed in Section 3.1.

Virus	Ligand	Immobilization	Matrix	Key Findings	Platform	Reference
Influenza A Virus, Strains X-31 and X-31 HAM	Human and avian receptor analogs: α2,6-sialyl-N-acetyllactosamine and α2,3-sialyl-N-acetyllactosamine	Streptavidin biosensor, biotinylated receptors	10 mM HEPES pH 7.4 150 mM NaCl 0.005% Tween-20 4 mM CaCl2	Novel assay to determine viral surface receptor balance based on virus binding to human and avian receptor analogs with and without neuraminidase inhibitors.	Octet RED (ForteBio, Menlo Park, CA, USA)	Benton et al., 2015 [40]
HK H3N2 hH3hN2, lacking the second binding site for NA and hH3aN2, containing the second binding site for NA viral strains. Avian NA contain a second binding site for sialic acid receptor.	2,3-sialyl-N-acetyllactosamine-N-acetyllactosamine and 2,6-sialyl-N-acetyllac- tosamine-N-acetyllactosamine and N-acetyllactosamine-N-acetyllactosamine and LAMP1 or glycophorin A glycoproteins	Streptavidin biosensor, biotinylated receptors	PBS with calcium and magnesium	The effects of the second binding site on NA should be considered in receptor balance studies.	Octet RED348	Du et al., 2019 [41]
Influenza A Virus, lab strains PR8MtSIN and PR8CAM2,3	Sialic acid receptors and Fc-tagged glycoproteins	Streptavidin biosensor, biotinylated receptors and Protein A biosensor	PBS with calcium and magnesium	Binding of influenza A virus to ligand is irreversible when NA cleavage activity is insignificant. koff ~ 0	Octet QK	Guo et al., 2018 [42]
H3N2	Human and avian receptor analogs: α2,6-sialyl lactosamine and α2,3-sialyl lactosamine	Streptavidin biosensor, biotinylated receptors	150 mM NaCl 10 mM Hepes pH 7.4 3 mM EDTA 100 μM oseltamivir carboxylate 0.005% Tween-20	Hemagglutinin Asp-225-Asn substitution is very critical in the decrease of human receptor binding from the 2004 to 2005 virus.	Octet RED	Lin et al., 2012 [43]
30 different H5N1 viruses	Human and avian receptor analogs: α2,6-sialyl lactosamine and α2,3-sialyl lactosamine	Streptavidin biosensor, biotinylated receptors	10 mM HEPES pH 7.4 150 mM NaCl 3 mM EDTA 0.005% Tween-20 Viral solutions incubated with 10 μM oseltamivir carboxylate and 10 μM zanamivir.	Analyzed three recombinant H5N1 viruses with BLI after agglutination studies. Mutations to residues 134 and 186 on HA result in weakened binding to human and avian receptor analogs.	Octet RED	Crusat et al., 2013 [44]
Recombinant H5N1	Human and avian receptor analogs: α2,6-linked sialic acid and α2,3-linked sialic acid	Streptavidin biosensors, biotinylated receptors	10 mM HEPES pH 7.4 150 mM NaCl 3 mM EDTA 0.005% Tween-20 10 μM oseltamivir carboxylate 10 μM zanamivir	Substitutions Asn186Lys and Ser227Asn in H5 clade 1 HA decrease affinity for avian receptor analog.	Octet RED	Xiong et al., 2014 [45]
H9N2–contemporary viruses of the zoonotic G1 lineage and representative viruses of the zoonotic BJ94 lineage	Human receptor analog: α2,6-sialyl lactosamine and Avian receptor analogs: α2,3-sialyl lactosamine, sulfated and non-sulfated	Streptavidin biosensors, biotinylated receptors	10 mM HEPES pH 7.4 150 mM NaCl 3 mM EDTA 0.005% Tween-20 10 μM oseltamivir carboxylate 10 μM zanamivir	KD values presented in Table 1 of study.	Octet RED	Peacock et al., 2017 [46]
H9N2	Human receptor analog: α2,6-sialyl lactosamine and Avian receptor analogs: α2,3-sialyl lactosamine, sulfated and non-sulfated	Streptavidin biosensors, biotinylated receptors	10 mM HEPES pH 7.4 150 mM NaCl 3 mM EDTA 0.005% Tween-20 10 μM oseltamivir carboxylate 10 μM zanamivir	The effects of mutagenesis on HA receptor-binding residues explained by BLI. Residues 190, 226, and 227 have large effects on receptor binding preference.	Octet RED	Peacock et al., 2021 [47]
Canine and feline parvovirus capsid	Transferrin receptor type 1 and scFv-Fcs	Ni-NTA biosensors, His-receptors and Protein A biosensors, scFv-Fcs	PBS, 0.02% ovalbumin 0.02% Tween-20	Determined association constants, dissociation constants, and binding affinity between the capsid and receptor/antibodies.	BLItz (ForteBio)	Callaway et al., 2018 [48]
DENV	Kazal-type serine protease inhibitor, AaTI and Plasmin	Ni-NTA biosensors, His-AaTI	50 mM Tris pH 7.5 100 mM NaCl 0.1% BSA buffer	Plasmin bound rAaTI with Kd of 62.8 nM.	Octet RED 96	Ramesh et al., 2019 [49]