Appendix A. Supplementary Material

Appendix A. Supplementary material

Encapsulation of metal cations (Cu2+, Zn2+, Ca2+ and Ba2+) by the Phe-Phe di-peptide investigated using natural bond orbital theory and molecular dynamics simulation

S. Bhunia, A. Singh, and A. K. Ojha

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Table S1 Computed relative energy values (kcal/mol) of Phe-Phe + 3 Cu2+/Zn2+ low energy conformers with the 6-31+G(d) basis set at B3LYP and MP2 level of theories.

Fig. S1 Molecular dynamics simulation’s trajectory for the binding motif 4 Phe-Phe + Cu2+/COO-Benzene using 90000 steps with an interval of 0.0001 ps at constant number of particles, pressure and temperature (NPT) at 300 K.

Fig. S2 Molecular dynamics simulation’s trajectory for the binding motif 5 Phe-Phe + Cu2+/CO-Benzene using 90000 steps with an interval of 0.0001 ps at constant number of particles, pressure and temperature (NPT) at 300 K.

Fig. S3 Molecular dynamics simulation’s trajectory for the binding motif 6 Phe-Phe + Zn2+/CO-Benzene using 90000 steps with an interval of 0.0001 ps at constant number of particles, pressure and temperature (NPT) at 300 K.

Fig. S4 Molecular dynamics simulation’s trajectory for the binding motif 7 2+ Phe-Phe + Zn /COO-NH-NH2 using 90000 steps with an interval of 0.0001 ps at constant number of particles, pressure and temperature (NPT) at 300 K.

Fig. S5 Molecular dynamics simulation’s trajectory for the binding motif 8 Phe-Phe + Zn2+/COO-Benzene using 90000 steps with an interval of 0.0001 ps at constant number of particles, pressure and temperature (NPT) at 300 K.

Fig. S6 Molecular dynamics simulation’s trajectory for the binding motif 9 Phe-Phe + Ca2+/CO-COOH-Benzene using 90000 steps with an interval of 0.0001 ps at constant number of particles, pressure and temperature (NPT) at 300 K.

Fig. S7 Molecular dynamics simulation’s trajectory for the binding motif 10 Phe-Phe + Ca2+ /CO-Benzene using 90000 steps with an interval of 0.0001 ps at constant number of particles, pressure and temperature (NPT) at 300 K. 1 Fig. S8 Molecular dynamics simulation’s trajectory for the binding motif 11 Phe-Phe + Ba2+/CO-COOH-Benzene using 90000 steps with an interval of 0.0001 ps at constant number of particles, pressure and temperature (NPT) at 300 K.

2 Table S1 Computed relative energy values (kcal/mol) of Phe-Phe + Cu2+/Zn2+ complexes employing the 6-31+G(d) basis set at B3LYP and MP2 level of theories.

Binding motifs B3LYP MP2 Phe-Phe + Cu2+ complex Phe-Phe + Cu2+/COO-Benzene 0.00 0.00 Phe-Phe + Cu2+/CO-Benzene 5.20 12.75 Phe-Phe + Cu2+/COOH-Benzene 9.08 16.13 2+ Phe-Phe + Cu / NH-NH2 27.86 31.14 Phe-Phe + Zn2+ complex Phe-Phe + Zn2+/CO-Benzene 0.00 0.00 2+ Phe-Phe + Zn /COO-NH-NH2 1.78 0.67 Phe-Phe + Zn2+/COO-Benzene 17.64 35.26 Phe-Phe + Zn2+/COOH-Benzene 32.54 63.54

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Fig. S8 10 11