Formation of titanium(IV) transferrin by reaction of human serum apotransferrin with titanium complexes |
| |
Institution: | 1. Department of Chemistry, University of Florence, via Gino Capponi 7, 50121 Florence, Italy;2. University of Horticulture and Food Industry, Budapest, Hungary;3. CNR Center on Metalloproteins, Padua, Italy |
| |
Abstract: | The reaction of human serum apotransferrin with titanium(IV) citrate under physiological conditions results in the formation of a specific bis-titanium(IV) transferrin adduct (Ti2Tf hereafter) with two titanium(IV) ions loaded at the iron binding sites. The same specific Ti2Tf complex is formed by reacting apotransferrin with titanium(III) chloride and exposing the sample to air. The derivative thus obtained was characterized by spectroscopic techniques, including absorption, UV difference, circular dichroism and 13C NMR spectroscopies, and shown to be stable within the pH range 5.5–9.0. Surprisingly, the reaction of apoTf with titanium(IV) nitrilotriacetate (NTA) does not lead to formation of appreciable amounts of Ti2Tf, even after long incubation times, although some weak interactions of Ti(IV)NTA with apoTf are spectroscopically detected. Implications of the present results for a role of transferrin in the uptake, transport and delivery of soluble titanium(IV) compounds under physiological conditions are discussed. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|