A chromophore-containing agglutinin from Haliclona manglaris: Purification and biochemical characterization

Abstract

A new chromophore-containing agglutinin (Haliclona manglaris agglutinin (HMA)) was isolated from the tropical sponge H. manglaris. HMA was purified by a combination of hydrophobic interaction chromatography and ion exchange chromatography. Native HMA is a heterotrimer formed by two β-chains (15 kDa) and one α-chain (22 kDa). HMA is a glycoprotein and possesses three intrachain disulfide bonds. Hemagglutinating activity of HMA was stable at neutral pH and temperatures up to 60 °C. HMA was only inhibited by thyroglobulin. Mass spectrometry sequencing and Edman degradation revealed a unique amino acid sequence of about 30%. Moreover, HMA has an organic chromophore of 581 Da, and this characteristic seems to be important to its antioxidant activity. Interestingly, while HMA showed no toxicity against Artemia nauplii and was unable to agglutinate bacterial cells, it did show a high capacity to protect β-carotene against oxidation. Thus, our findings suggest the putative involvement of HMA in the protection of the sponge against oxidation.

Purification, biochemical characterization of a lectin from marine sponge Ircinia strobilina and its effect on the inhibition of bacterial biofilms

“…Other sponge lectins also did not show amino acid sequence similarity with proteins deposited in databases, such as HMA -Haliclona manglaris agglutinin, and H-3 from Haliclona caerulea (Carneiro et al 2015(Carneiro et al , 2013a.…”

“…This role is quite important, since invertebrates do not have an adaptive immune system (Smith et al 1999). However, other biological functions are also attributed to sponge lectins suggesting that these proteins could be involved in symbiosis, cellular interactions and morphogenesis, cell aggregation, spicule formation, growth regulation and oxidative photoprotection (Gundacker et al 2001, Carneiro et al 2015, Garderes et al 2015, Müller et al 1981, Funayama et al 2005.…”