Study of D2O solutions of albumin by 400 MHz NMR in the presence of and absence of Mn (II)

1/T1 and 1/T2 values of H2O solutions of albumin were studied in the presence and absence of Mn(II) in the previous studies in detail. D2O solutions were also used for supplementary experiments. However, these studies were carried out rather at low frequencies. Thus, studying of 1/T1 and 1/T2 values of D2O solutions of albumin containing Mn(II) ions by 400 MHz will be a novelty. In the present studies, 1/T1 and 1/T2 ratios of D2O and 0.1 H2O/0.9 D2O solutions were investigated; a) Without addition of albumin and ion, b) With respect to ion concentration in the presence of constant albumin, c) With respect to protein concentration for constant ion concentration. The experiments were carried out by using Bruker Avance 400 MHz NMR. Inversion Recovery (180-?-90) pulse step were used for T1, whereas Carr-Purcell-Meiboom-Gill pulse step were used for T2. These experiments were carried out at 25 °C. 1/T1 and 1/T2 ratios of some samples were also measured in terms of temperature. The experiments were performed for temperature range of 20°C-40°C by using automatic temperature control unit. 1/T1 and 1/T2 values increase linearly with concentration increase in all concentration experiments. Proton T2 relaxivity of D2O solution is remarkable different from proton T2 relaxivity , which decreases slightly by the addition of H2O. Although T1 mechanism becomes dipolar by the addition of water, very high T2 relaxivity implies that T2 occurs by spin rotation or by other mechanism.