Structure and anticancer activity of a new lectin from the cultivated red alga, Kappaphycus striatus

Abstract

The red alga Kappaphycus striatus is economically important food species and extensively cultivated throughout most tropical parts of the world as a source of carrageenan. In this note, the primary structure of a new lectin KSL from this alga was elucidated by the rapid amplification method of complementary DNA (cDNA) ends, which consists of 267 amino acid residues distributed in four tandem-repeated domains of about 67 amino acids and sharing 43% of identity. The calculated molecular mass from the deduced sequence was consistent with that of natural KSL (27,826 Da) determined by electron spray ionization-mass spectrometry. The primary structure of KSL showed high similarity to those of the high mannose N-glycan specific lectins from marine red algae, ESA-2 from Eucheuma serra, EDA-2 from Eucheuma denticulatum, KSA-2 from Kappaphycus striatum, KAAs from Kappaphycus alvarezii and SfLs from Solieria filiformis, and from microorganisms, BOA from Burkholderia oklahomensis, MBHA from Myxococcus xanthus, OAA from Oscillatoria agardhii and PFL from Pseudomonas fluorescens. Furthermore, KSL showed anticancer effects against five carcinoma cell lines, HT29, Hela, MCF-7, SK-LU-1 and AGS, in a dose-dependent manner with the IC 50 values of 0.80-1.94 µM, whereas its inhibition activities on cancer cells were not detected in the presence of yeast mannan, an inhibitor against lectin KSL. The cultivated red alga K. striatus could also be a good source of functional lectin(s) for application as anticancer agents.

Anti-inflammatory, remorin-like protein from green marine Macroalga Caulerpa sertularioides (S.G.Gmel.) M.Howe

“…For example, a lectin isolated from Glycine max was about 31 kDa [ 65 ], whereas, a lectin isolated from red seaweed Alsidium triquetrum (formerly Bryothamnion triquetrum ) was only 8 kDa [ 61 ]. However, high molecular weight lectins were also reported from some seaweeds, includingincluding 30 kDa from a red seaweed Amansia multifidi [ 66 ]; 66 kDa lectin was reported from red seaweed Gracilaria cornea [ 67 ]; 23–44 kDa from Caulerpa cuppressoides [ 68 ]; 28 kDa lectin from a red seaweed Kappaphycus striatus [ 69 ]; 17 kDa lectin from a red seaweed Gracilaria eucheumatoides (formerly Hydropuntia eucheumatoides ) [ 70 ]; 53.8 kDa lectin from a green seaweed Bryopsis plumosa [ 48 ]; 21.5 kDa from a red seaweed Georgiella confluens [ 50 ]. In the present study, a single band was visible only for Caulerpa sertularioides (CS) at a molecular mass ∼17 kDa.…”

An Update of Lectins from Marine Organisms: Characterization, Extraction Methodology, and Potential Biofunctional Applications

“…Red alga ( Kappaphycus striatus) lectin displayed antiproliferative activity against AGS gastric cancer cells, Hela cervical cancer cells, HT29 colorectal cancer cells, MCF-7 breast cancer cells, and SK-LU-1 lung denocarcinoma cells, with IC50 values in the range of 0.8–1.94 µM. Yeast mannan, which inhibited the lectin, abolished the anticancer effect of the lectin [ 226 ]. The IC50 values of the cytotoxic activity of acetyl hexosamine-binding Japanese black sponge ( Halichondria okadai ) lectin on breast cancer MCF-7 cells and T47D cells and cervical cancer HeLa cells, were 52, 63 and 40 μg/m, respectively.…”

N-acetylneuraminic acid specific lectin and antibacterial activity from the red alga Gracilaria canaliculata Sonder

“…Нещодавно деякі лектини, виділені з еукаріотичних морських водоростей, привернули увагу вчених як потенційні джерела нових речовин з противірусною (ВІЛ, SARS-CoV та віруси грипу) та протипухлинною активністю (O' Keefe et al, 2010;Sato et al, 2011aSato et al, , b, 2015Hirayama et al, 2016;Mu et al, 2017;Chaves et al, 2018a;Barre et al, 2019Barre et al, , 2020Hung, Trinh, 2020;Sohrab et al, 2020). Це обумовлено їхньою здатністю зв'язувати вуглеводні структури, присутні на глікопротеїновій оболонці вірусу або на поверхнях ракових клітин, блокуючи потрапляння вірусів у клітини-господарі або інгібуючи ріст ракових клітин.…”