Influence of protein dynamics on the metal-sites of ovotransferrin

✍ Scribed by F. J. Schwab; H. Appel; M. Neu; W.-G. Thies

• Publisher: Springer
• Year: 1992
• Tongue: English
• Weight: 813 KB
• Volume: 21
• Category: Article
• ISSN: 1432-1017
• DOI: 10.1007/bf00185429

✦ Synopsis

Using the perturbed angular correlations (PAC) technique, the formation of hafnium-ovotransferrin complexes has been studied. Two binding configurations at each of the two specific binding-sites of the protein have been observed. They are characterized by well-defined electric quadrupole frequencies. Information about the dynamics of the protein was derived from temperature dependent measurements of the relaxation constant. The well-resolved spectra taken with fast BaF2-detectors allow a precise determination of the relaxation behaviour of the protein. The results are compared with the predictions from a hydrodynamic model for the reorientation of macromolecules. Thus the hydrodynamic volume of ovotransferrin and its N-terminal half-molecule were determined. The ovotransferrin volume is in agreement with a value derived for human serum transferrin from small angle neutron scattering. From experiments with immobilized protein material there is evidence for internal protein dynamics which is probed by the Hf-ion bound to the specific metal-sites.