Purify Bombesin by gel filtration on a small column of Sephadex G-10 and elute with 0.01 M AcOH. This procedure removes lower molecular weight contaminants which are retarded on the column. The procedure should be repeated twice, and the material should now be homogeneous on electrophoresis, and on chromatography it gives a single active spot which is negative to ninhydrin but positive to Cl2 and iodoplatinate reagents. RF on paper chromatography (n-BuOH/pyridine/AcOH/H2O :: 37.5: 25:7.5:30) is 0.55 for Bombesin and 0.65 for Alytin. [Bernardi et al. Experientia Part 1 27 166 1971, Anastasi et al. Part 2 27 873 1971.] The hydrochloride has m 185o(dec) (from EtOH) [] D -20.6o [c 0.65, Me2NCHO/(Me2N)3PO (8:2)]. [For the stimulation of inositol phosphate see Lloyd et al. Biochem J 260 813 1989.]
