Toward the Construction of 3D Dipeptide–Metal Frameworks

Abstract

Single amino acids have been vastly used to generate metal−biomolecule frameworks. Three-dimensional (3D) frameworks based on di-and tripeptide frameworks remain nevertheless quite scarce. We report the preparation of unique 3D dipeptide−metal frameworks in which both amino acid residues participate in metal coordination and in the construction of the networks.2

Biologically derived metal organic frameworks

“…[65] Peptide derived bio-MOFs constructed from networks made from dipeptides such as [Zn (GlyThr) 2] results in the generation of 1-dimensional channels, however in the former bio-MOF, the presence of Thr leads in the formation of strong interactions with the adjacent layer, reinforcing the stability in the 3-dimensional crystal structure. [106] For the latter [Zn(GlyAla)2], the pores collapse upon desolvation but they can be recovered when polar molecules diffuse into its pores. [105] GlyAsp based bio-MOFs can be prepared with either Co II or Zn II generating 3-dimensional frameworks with different topologies (Table 2, entry 7 and 8, respectively).…”

“…[105] GlyAsp based bio-MOFs can be prepared with either Co II or Zn II generating 3-dimensional frameworks with different topologies (Table 2, entry 7 and 8, respectively). [106] The structure of the Co II framework consists of dipeptides connecting four metal ions, and a unique seven membered ring formed through the coordination of a metal ion with alpha and beta carboxylate groups of the Asp residue in the dipeptide. [106] In this structure, the dimensionality arises from the side chains of Asp bridging two Co II ions.…”

“…[106] The structure of the Co II framework consists of dipeptides connecting four metal ions, and a unique seven membered ring formed through the coordination of a metal ion with alpha and beta carboxylate groups of the Asp residue in the dipeptide. [106] In this structure, the dimensionality arises from the side chains of Asp bridging two Co II ions. In the Zn II framework, the metal center is penta-coordinated, with each dipeptide connecting four Zn metal ions through a five-membered glycinate chelate ring.…”

“…In the Zn II framework, the metal center is penta-coordinated, with each dipeptide connecting four Zn metal ions through a five-membered glycinate chelate ring. [106] While the coordination mode of Co II and orientation of GlyAsp results in the formation of a 3-dimensional framework, the Zn II based bio-MOF gives a 2-dimensional structure with layer parallel to the ab plane, and a rigid conformation of GlyAsp dipeptide with water molecules trapped in the intersheet plane. [106] Changing the bio-ligand to GlySer, the reposition of the OHbearing Ser side chain allows for ordered cooperative, displacive, and conformational changes of the peptide (Table 2, entry 9).…”

“…[106] While the coordination mode of Co II and orientation of GlyAsp results in the formation of a 3-dimensional framework, the Zn II based bio-MOF gives a 2-dimensional structure with layer parallel to the ab plane, and a rigid conformation of GlyAsp dipeptide with water molecules trapped in the intersheet plane. [106] Changing the bio-ligand to GlySer, the reposition of the OHbearing Ser side chain allows for ordered cooperative, displacive, and conformational changes of the peptide (Table 2, entry 9). [107] This change from a methyl, to a primary alcohol, is a sufficient change in the framework to go from a solvated porous state (GlyAla) to a nonporous state.…”