The isolation and detection of non-collagenous proteins from the compact bone of the dinosaur Iguanodon

This report describes the isolation of guanidinium chloride extractable pro tein from demineralised bone extracts obtained from the 125-130 mya dinosau r Iguanodon. Protein products were isolated in the Mr. range 5,000-66,000 u sing SDS-PAGE and represent the first electrophoretically defined proteins isolated from dinosaur tissues. The levels of glycine, aspartate and serine tentatively suggest the presence of phosphoproteins. Hydroxylysine and hyd roxy proline were not detected, confirming the presence of non-collagenous material. In addition the absence of ornithine confirmed lack of bacterial contamination. The relatively high level of leucine in the 2MNaCl NaCl frac tions together with the abolition of alcian blue reactivity following prote ase-free chondroitinase digestion suggests the presence of proteoglycans. T he study is of interest in describing the early proteins laid down in miner alised tissues for epitactic crystal growth and may provide evidence on evo lutionary aspects of bone proteins.