Characterization of a Novel Mannose-Binding Lectin with Antiviral Activities from Red Alga, Grateloupia chiangii

Abstract

Lectins have the ability to bind specific carbohydrates and they have potential applications as medical and pharmacological agents. The unique structure and usefulness of red algal lectin have been reported, but these lectins are limited to a few marine algal groups. In this study, a novel mannose-binding lectin from Grateloupia chiangii (G. chiangii lectin, GCL) was purified using antiviral screens and affinity chromatography. We characterized the molecular weight, agglutination activity, hemagglutination activity, and heat stability of GCL. To determine the carbohydrate specificity, a glycan microarray was performed. GCL showed strong binding affinity for Maltohexaose-β-Sp1 and Maltoheptaose-β-Sp1 with weak affinity for other monosaccharides and preferred binding to high-mannan structures. The N-terminal sequence and peptide sequence of GCL were determined using an Edman degradation method and LC-MS/MS, and the cDNA and peptide sequences were deduced. GCL was shown to consist of 231 amino acids (24.9 kDa) and the N-terminus methionine was eliminated after translation. GCL possessed a tandem repeat structure of six domains, similar to the other red algal lectins. The mannose binding properties and tandem repeat structure of GCL may confer it the potential to act as an antiviral agent for protection against viral infection.

Natural product-derived phytochemicals as potential agents against coronaviruses: A review

“…Plant lectins, which are proteins that can bind specifically and reversibly to carbohydrate groups (Mitchell et al, 2017), are another group of naturally occurring compounds that may inhibit SARS-CoV. Lectins have shown promise as antiviral agents against viruses such as influenza and herpes simplex virus (Hwang et al, 2020), as well as Ebola (Covés-Datson et al, 2019;Michelow et al, 2011). Remarkably, elevating the plasma levels of recombinant human mannose-binding lectin in mice allowed them to survive otherwise fatal Ebola infections (Michelow et al, 2011).…”

Anti-herpetic Activity of Macrocystis pyrifera and Durvillaea antarctica Algae Extracts Against HSV-1 and HSV-2

“…Interestingly, polysaccharides such as sulfated fucans and sulfated xylogalactofucan from different types of algae have been shown to inhibit HSV-1 or HSV-2 attachment to host cells ( Mazumder et al, 2002 ; Adhikari et al, 2006 ; Mandal et al, 2008 ; Saha et al, 2012 ). On the other hand, lectins and phycobiliproteins derived from algae have also been shown to have antiviral activities against HSVs ( Shahidi and Rahman, 2018 ; Hwang et al, 2020 ). A well-characterized alga protein with anti-herpetic activity is Griffithsin (GRFT), a lectin isolated from the marine red alga Griffithsia sp., which can interact with specific glycan structures present in glycoproteins on the surface of the viral envelope and that interferes with virus binding to the surface of target cells ( Mori et al, 2005 ; Levendosky et al, 2015 ; Lusvarghi and Bewley, 2016 ; Derby et al, 2018 ).…”

Role of food nutrients and supplementation in fighting against viral infections and boosting immunity: A review

“…They can recognize the virus and irreversibly bind with the sugars through their binding sites. Lectins are affective against viruses such as HIV, influenza, Hepatitis C virus, and coronaviruses ( Hwang et al, 2020 ; Mazalovska & Kouokam, 2018 ). In this sense, most of the mannose-binding lectins showed antiviral effect against the coronaviruses (SARS-CoV) ( Keyaerts et al, 2007 ).…”