Microcystis viridis NIES-102 strain, a unicellular freshwater bloom-forming cyanobacterium, showed transient hemagglutinating activity in laboratory culture during stationary phase under nonaeration conditions. However, the hemagglutinating activity which was inhibited with yeast mannan could not be observed during culture with aeration. A mannan-binding lectin named MVL was isolated with the assay of the hemagglutinating activity against rabbit erythrocytes from the cyanobacterium by successive hydrophobic and gel filtration chromatography. MVL was composed of a single polypeptide of 13 kDa. The gene (mvl) for MVL was cloned from a genomic DNA of NIES-102 strain as a template, and its sequence was determined. The deduced amino acid sequence showed that MVL consisted of 113 amino acid residues and was composed of two tandemly repeated homologous domains of 54 amino acid residues. MVL showed no sequence homology to any other lectins or proteins.(アオコによる湖沼汚染の原因種であるシアノバクテリアの一種、M.viridis(NIES102)から、初めて糖鎖認識タンパク質レクチンを単離し、精製法の確立、タンパク質の分子構造(一次構造)を明らかにし、特徴ある繰り返し配列を発見するとともに、糖鎖結合特異性について調べた。またこの繰り返し配列は糖鎖を認識し結合する部位であることを推察した。この分子をMVLと名付けた。これまで未解明だったシアノバクテリアのレクチンタンパク質の分子構造が明らかになり、レクチンの生理機能の解明と併せて産業利用分野への道筋を開いた。)
pp.703-708
Yamaguchi M, Ogawa T, Muramoto K, Kamio Y, Jimbo M, Kamiya H.
