New affinity procedure for the isolation and further characterization of the blood group B specific lectin from the red marine alga Ptilota plumosa

• Published in: Journal of applied phycology 2002-12, Vol.14 (6), p.489-495
• Main Authors: SAMPAIO, Alexandre H, ROGERS, David J, BARWELL, Clive J, SAKER-SAMPAIO, Silvana, NASCIMENTO, Kyria S, NAGANO, Celso S, FARIAS, Wladimir R. L
• Format: Article
• Language: English
• Subjects: affinity chromatography; Analytical, structural and metabolic biochemistry; Biological and medical sciences; blood group B specific lectin; Fundamental and applied biological sciences. Psychology; Glycoproteins; Proteins; Ptilota plumosa; Rhodophyta
• ISSN: 0921-8971; 1573-5176
• DOI: 10.1023/A:1022327010736

The red marine alga Ptilota plumosa has been shown to contain an anti-human blood group B lectin. We report here a new isolation procedure by affinity chromatography on Sephadex G-200 and characterisation of the isolated lectin. The M sub(r), determined by gel filtration, was 52,500. SDS-PAGE revealed a single protein band with M sub(r) 17,440, indicating the native lectin was a trimer of subunits with the same M sub(r), as reported for the lectins from two other Ptilota species, P. filicina and P. serrata. Analysis of amino acid composition showed slightly more basic than acidic amino acids. This was in contrast to the P. filicina and P. serrata lectins previously found to contain a higher proportion of acidic than basic amino acids. Haemagglutination inhibition tests showed the P. plumosa lectin was inhibited by galactose, glucose and their derivatives with p-nitrophenyl- alpha -D-galactoside most strongly inhibitory. All glycoproteins tested failed to inhibit the lectin. The amino acid composition, human blood group-B specificity and lack of inhibition by glycoproteins indicate the lectin from P. plumosa possesses unique characteristics among marine algal lectins.