This data characterizes binding of Zn2+ and Gd3+ to engineered nanosheets at 40C and in a brine solution. The engineered nanosheets are composed of surface-layer (S-layer) proteins which form 2 D crystalline sheets and display Zn2+- or Gd3+-binding domains on these sheets. Their ability to bind Zn2+ is compared to S-layer nanosheets that do not contain Zn2+-binding domains. We found that the purification method of these nanosheets was a critical determinant of their function and thus have provided data on the binding from two different purification methods. A key distinction of this dataset from other datasets is that the engineered nanosheets were expressed and purified from E. coli grown at 37C as described in (Kinns, 2010; Howorka, 2000), References: Kinns, H., et al. Identifying assembly-inhibiting and assembly-tolerant sites in the SbsB S-layer protein from Geobacillus stearothermophilus. Journal of Molecular Biology, 2010. 395(4): p. 742-753. Howorka, S., et al. Surface-accessible residues in the monomeric and assembled forms of a bacterial surface layer protein. Journal of Biological Chemistry, 2000. 275(48): p. 37876-37886.