Spectroscopic Studies for Rhodium (III) Binding to Apo-Transferrin

Table 1

Secondary structure determination for free ApoHST (0.5 mM) and Rh(III)-ApoHST coordinates (0.25, 0.5, and 1 mM metal ion concentrations).

Components amide I (cm^-1)	Free ApoHST (%) (0.5 mM)	Rh(III) - ApoHST 0.25 mM coordinate; ApoHST:Rh(III) =1 : 0.5(%)	Rh(III) - ApoHST 0.5 mM coordinate; ApoHST:Rh(III) =1 : 1(%)	Rh(III) - ApoHST 1 mM coordinate; ApoHST:Rh(III) =1 : 2(%)
β–Sheet; 1637-1614 (±2)	23	32	41	43
α–Helix; 1660-1650 (±4)	53	49 (-7.5%)	42 (-20.7%)	39 (-26.4%)
β-Turn; 1678-1670 (±2)	10	13	11	12
β–Antiparallel; 1692-1680 (±2)	14	06	06	06

Percentage variations in ApoHST α-helix content upon coordination with Rh(III) ion at physiological pH and room temperature.