The hemagglutinin-like proteins of basal vertebrate influenza-like viruses exhibit sialic-acid receptor binding disparity and their structural bases.

ABSTRACT: In 2018, two novel influenza-like virus genomes were first identified in basal vertebrates: the Asiatic toads (Bufo gargarizans) and spiny eels (Mastacembelus aculeatus). Their hemagglutinin (HA) proteins exhibit remarkably low amino acid sequences homology (23.0% and 42.8%, respectively) compared to influenza B virus (IBV), their closest canonical influenza virus relative. This study revealed that the Asiatic toad influenza-like virus HA (tHA) demonstrates dual receptor specificity, bound both α2-3 (avian-type) and α2-6 (human-type) sialic acid (SA) receptors, whereas the spiny eel influenza-like virus HA (eHA) lacks this capability. Biophysical characterization showed reduced thermal stability (lower Tm values) for both tHA and eHA compared to canonical influenza HA. Furthermore, we dete

SUBMITTER: Zhang D 

PROVIDER: S-EPMC12654924 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature