A Complex-Type N -Glycan-Specific Lectin Isolated from Green Alga Halimeda borneensis Exhibits Potent Anti-Influenza Virus Activity

• Published in: International journal of molecular sciences Vol. 25; no. 8; p. 4345
• Main Authors: Mu, Jinmin, Hirayama, Makoto, Morimoto, Kinjiro, Hori, Kanji
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 15.04.2024
• Subjects: Algae; Animals; anti-influenza virus activity; Antiviral Agents - chemistry; Antiviral Agents - pharmacology; Chlorophyta - chemistry; Chromatography; complex N-glycan binding specificity; Glycoproteins; green alga; Halimeda borneensis; Humans; Infections; Influenza; Influenza A Virus, H3N2 Subtype - drug effects; lectin; Lectins; Lectins - chemistry; Lectins - isolation & purification; Lectins - metabolism; Lectins - pharmacology; Molecular structure; Polysaccharides - chemistry; Polysaccharides - pharmacology; Proteins; Viral infections; Viruses; complex N-glycan binding specificity; green alga; lectin; Halimeda borneensis; anti-influenza virus activity
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms25084345

Marine algal lectins specific for high-mannose -glycans have attracted attention because they strongly inhibit the entry of enveloped viruses, including influenza viruses and SARS-CoV-2, into host cells by binding to high-mannose-type -glycans on viral surfaces. Here, we report a novel anti-influenza virus lectin (named HBL40), specific for complex-type -glycans, which was isolated from a marine green alga, . The hemagglutination activity of HBL40 was inhibited with both complex-type -glycan and -glycan-linked glycoproteins but not with high-mannose-type -glycan-linked glycoproteins or any of the monosaccharides examined. In the oligosaccharide-binding experiment using 26 pyridylaminated oligosaccharides, HBL40 only bound to complex-type -glycans with bi- and triantennary-branched sugar chains. The sialylation, core fucosylation, and the increased number of branched antennae of the -glycans lowered the binding activity with HBL40. Interestingly, the lectin potently inhibited the infection of influenza virus (A/H3N2/Udorn/72) into NCI-H292 cells at IC of 8.02 nM by binding to glycosylated viral hemagglutinin (K of 1.21 × 10 M). HBL40 consisted of two isolectins with slightly different molecular masses to each other that could be separated by reverse-phase HPLC. Both isolectins shared the same 16 -terminal amino acid sequences. Thus, HBL40 could be useful as an antivirus lectin specific for complex-type -glycans.