Nuclear magnetic relaxation dispersion of ferritin and ferritin-like magnetic particle solutions: A pH-effect study

✍ Scribed by Yves Gossuin; Alain Roch; Francesco Lo Bue; Robert N. Muller; Pierre Gillis

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 159 KB
• Volume: 46
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.1216

✦ Synopsis

Abstract

The relaxation mechanism of water protons in the presence of ferritin is still being debated. In this work, the pH dependence of the relaxation induced by ferritin and Fercayl®, a ferritin‐like akaganeite particle, is studied through T~1~ and T~2~ nuclear magnetic relaxation dispersion (NMRD) profiles. To differing extents, the relaxation brought about by both systems is significantly affected by pH. A proton exchange time of 33 ns (at pH 6 and 37°C) is deduced from the fittings of Fercayl® T~1~ NMRD profiles. The linearity of the relationship between 1/T~2~ and the magnetic field B~0~ for ferritin and Fercayl® solutions is not altered by changes in pH. The parameters of this linearity strongly depend on pH for the latter, while remaining unchanged for the former. These results are interpreted in terms of an exchange between protons belonging to hydroxyl groups at the surface of the particle and bulk water protons. Magn Reson Med 46:476–481, 2001. © 2001 Wiley‐Liss, Inc.