Methods of sequestering target elements
Provided herein are methods of sequestering target elements (e.g., rare earth elements and/or radiometals) from a sample, methods of purifying target elements from samples, pharmaceutical compositions comprising target elements, and methods of treating a subject with said pharmaceutical compositions.
1 . A method of sequestering a target element from a sample,
the method comprising:
contacting the sample and a lanmodulin protein (LanM protein) in a first solution such that the target element (TE) binds to the LanM protein to form TE-LanM, wherein the first solution is aqueous and has a pH of 2.5 to 6.5, the target element is selected from a rare-earth element (REE), Bi, Tl, and In,
wherein the LanM protein comprises at least one LanM unit, wherein the at least one LanM unit is a portion of the LanM protein comprising at least two EF hand motifs,
wherein at least one of the EF hand motifs is of the form SEQ ID NO: 2 and at least two of the EF hand motifs of the LanM protein are separated by a space of 10-15 residues,
wherein the LanM protein is selected from:
a) wild-type lanmodulin comprising the sequence of SEQ ID NO: 1,
b) homologs of wild-type lanmodulin comprising the at least one LanM unit, and
c) a protein having portions comprising the at least at one LanM unit;
recovering the TE-LanM from the first solution by separating the TE-LanM from the sample and LanM protein to form a second solution comprising the TE-LanM;
adjusting the pH of the second solution to less than 2.5, wherein at the pH less than 2.5, the TE desorbs from the LanM protein;
separating the LanM protein and the TE; and
repeating the contacting, recovering, and adjusting steps with a second sample and the LanM protein at least once.
2 . The method of claim 1 , wherein the TE is one or more rare earth elements selected from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.
3 . The method of claim 1 , wherein the contacting step is performed at a temperature of 0° C. to 100° C.
4 . The method of claim 1 , wherein the contacting step is performed at a pressure of 0.1 atm to 5 atm.
5 . The method of claim 1 , wherein the LanM protein has a TE selectivity of 10 3 or more.
6 . The method of claim 1 , wherein the sample is an industrial feedstock comprising TEs and non-target elements and the industrial feedstock is non-combusted coal, electronic waste, natural waters, waste streams, radioisotope production compositions, industrial effluents, ore deposits, or a combination thereof.
7 . The method of claim 1 , wherein the recovery yield of TEs from the sample is 80% or more.
8 . The method of claim 1 , wherein the TE comprises a radioactive isotope selected from one or more of 44 Sc, 47 Sc, 90 Y, 134 Ce, 134 La, 86 Y, 88 Y, 139 Ce, 149 Th, 153 Gd, 177 Lu, 165 Dy, 152 Eu, 153 Sm, 147 Pm, 166 Ho, 169 Yb, 176 Yb, 152 Tb, 155 Tb, and 161 Tb.
9 . The method of claim 1 , wherein the sample is a pharmaceutical composition.
10 . The method of claim 1 , wherein the LanM protein includes a homolog of wild-type lanmodulin comprising the sequence selected from the group consisting of: SEQ ID NO: 3, SEQ ID NO: 4, and SEQ ID NO: 5.