Figure 1. Secretion of Zebrafish Cobalamin-binding Protein to the Ambient Water.

Five zebrafish were kept in 100 ml tapped water for six hours and content of cobalamin (A) and unsaturated cobalamin binding capacity (B) in the zebrafish ambient water was measured and compared to the values found in zebrafish protein extracts. Mean and SEM of three independent studies are indicated. (C) Size exclusion chromatography of the cobalamin binders found in zebrafish protein extract (full drawn line) and in collected zebrafish-ambient-water (black dashed line) measured as unsaturated cobalamin binding capacity, ⁵⁷[Co]-cobalamin (57Co-Cbl) (left Y-axis), and as amount of protein-bound cobalamin (Cbl) in the protein extract (grey dashed line) (right Y-axis). X-axis indicates the fraction number. Elution volume for void volume (V₀), human HC, IF, TC, and total volume (V_t) are shown by arrows.