%0 Journal Article %A Watanabe, Fumio %A Nakano, Yoshihisa %A Ochi, Hirotomo %A Kitaoka, Shozaburo %T Purification, Some Properties and Possible Physiological Role of an Extracellular Cobalamin Binding Protein from Euglena gracilis %D 1988 %J Microbiology, %V 134 %N 5 %P 1385-1389 %@ 1465-2080 %R https://doi.org/10.1099/00221287-134-5-1385 %I Microbiology Society, %X The extracellular cobalamin (Cbl) binding protein from Euglena gracilis was purified and some properties of the protein were studied for the elucidation of its physiological role. The protein was purified about 20-fold with a yield of 15% and was homogeneous on PAGE. SDS-PAGE indicated that the protein had a single type of polypeptide of M r 56000. The protein could bind some Cbl analogues with different β-coordination moieties, over a wide range of pH values from 4·0 to 9·0, and the K s value for cyanocobalamin was 1·1 nm. The extracellular Cbl binding protein was located on the cell surface of E. gracilis, probably bound in the muciferous layer. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-134-5-1385