Fig. 4

Lipid-binding by proteins in D. renale pseudocoelomic fluid. a Native (non-SDS) polyacrylamide gel electrophoresis of adult worm PCF and the fatty acid-binding recombinant ABA-1A of Ascaris suum as a control. Coomassie Blue stained gel. b The same as (a) gel in which protein samples were pre-incubated with the environment-sensitive fluorescent fatty acid analogue DAUDA before electrophoresis, viewed under ultraviolet light, and the negative image of DAUDA’s fluorescence emission is shown. Proteins migrating commensurate with P44 and ABA-1A in size associate with DAUDA indicative of lipid-binding activity. c Similar, unstained gel viewed under visible light is which only the intensely red P17 is visible. P17 loses its colour under SDS-PAGE (not shown), indicating that the red chromophore is not covalently bound. Comparison with (b) shows that P44, but not P17, binds DAUDA, which was also found to be the case in spectrofluorimetry (see main text)