A NOVEL PROCEDURE TO ISOLATE THE CHROMOPROTEINS IN THE PARAFLAGELLAR BODY OF THE FLAGELLATE EUGLENA-GRACILIS

The putative photoreceptor for phototaxis, the paraflagellar body (PFB), in the flagellate Euglena gracilis is localized at the base of the major flagellum. Flagella were isolated from Euglena and from the closely related Astasia longa. In Euglena the PFB remains attached to the isolated flagella. Since the colourless Astasia does not possess a PFB, isolated Astasia flagella serve as a control. Using liquid chromatography on a SMART system, the separation of the solubilized flagella yielded six major protein fractions. Fluorescence spectroscopy indicated the presence of flavin- and pterin-binding proteins in the PFB-flagella sample. The separated protein fractions were analysed by gel electrophoresis. The flavin-binding protein showed an apparent molecular mass of 31 000 while the pterin-binding proteins had apparent molecular masses between 24 000 and 28 800. These chromoproteins were not found in the Astasia control.