Solution- and Solid-State Evidence for Alkali Metal Cation−π Interactions with Indole, the Side Chain of Tryptophan

Wall, Stephen L. De; Meadows, Eric S.; Barbour, and Leonard J.; Gokel, George W.

doi:10.1021/ja9907921

Cited by 119 publications

(96 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular, for 44 cation±% interactions involving a sodium ion deposited in the Cambridge Structural Database (Allen & Kennard, 1993), the distances between the aromatic C atom and Na + range from 2.83 to 4.95 A Ê . Con®rmation of cation±% interaction between alkali-metal ions and the indole ring were recently discussed for synthetic compounds (De Wall et al, 1999). Their experimental results show that in the case of their synthetic receptors, the pyrrolo rather than the benzo ring is the % donor.…”

Section: Resultsmentioning

confidence: 99%

Identification of a potential metal cation–π binding site in the structure of a thermophilicBacillus stearothermophilustriosephosphate isomerase mutant

Maes¹

2000

Acta Crystallogr D Biol Cryst

View full text Add to dashboard Cite

A potential metal cation±% interaction between a sodium cation (Na + ) and the indole ring of a tryptophan residue was detected in the crystallographic structure (2 A Ê ) of the thermophilic Bacillus stearothermophilus triosephosphate isomerase H12N/K13G mutant (bTIMmut). The cation±% binding site is located near the surface of the protein, the alkali metal ion facing the benzo ring of Trp9. The presence of Phe21 and Glu17 close to Trp9 could indicate an additional role for those residues in the stability of the sodium±indole interaction. The sodium cation lies in a position that is occupied by CE and NZ of Lys13 in the wild-type structure.

show abstract

Section: Resultsmentioning

confidence: 99%

Identification of a potential metal cation–π binding site in the structure of a thermophilicBacillus stearothermophilustriosephosphate isomerase mutant

Maes¹

2000

Acta Crystallogr D Biol Cryst

View full text Add to dashboard Cite

show abstract

“…N,N-bis(2-(3-indolyl)ethyl)-4,13-diaza-18-crown-6,3. This compound was prepared as previously described (30). …”

Section: Nn-bis(2-(4-hydroxyphenyl)ethyl)-413-diaza-18-crown-62mentioning

confidence: 99%

“…We have recently reported compounds 2 and 3, which incorporate the electron-rich systems phenol and indole, respectively (29,30). In both receptors, K ϩ was bound as a sandwich complex.…”

mentioning

confidence: 99%

Synthetic receptors as models for alkali metal cation-π binding sites in proteins

Wall

Meadows

Barbour

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

100

View full text Add to dashboard Cite

The alkali metal cations Na ؉ and K ؉ have several important physiological roles, including modulating enzyme activity. Recent work has suggested that alkali metal cations may be coordinated by systems, such as the aromatic amino acid side chains. The ability of K ؉ to interact with an aromatic ring has been assessed by preparing a family of synthetic receptors that incorporate the aromatic side chains of phenylalanine, tyrosine, and tryptophan. These receptors are constructed around a diaza-18-crown-6 scaffold, which serves as the primary binding site for an alkali metal cation. The ability of the aromatic rings to coordinate a cation was determined by crystallizing each of the receptors in the presence of K ؉ and by solving the solid state structures. In all cases, complexation of K ؉ by the system was observed. When possible, the structures of the unbound receptors also were determined for comparison. Further proof that the aromatic ring makes an energetically favorable interaction with the cation was obtained by preparing a receptor in which the arene was perfluorinated. Fluorination of the arene reverses the electrostatics, but the aromaticity is maintained. The fluorinated arene rings do not coordinate the cation in the solid state structure of the K ؉ complex. Thus, the results of the predicted electrostatic reversal were confirmed. Finally, the biological implications of the alkali metal cation-interaction are addressed.

show abstract

“…With free indole as a ligand, metal ions typically show a preference for binding on the aryl ring of the bicyclic system [21][22][23]; however, in metal ion-Trp complexes [16,[24][25][26], or in other environments where competing binding sites are available [27,28], additional geometrical constraints imposed by chelation with oxygens, nitrogens, or other electron-rich binding sites become important and the lowest-energy isomers, tridentate chargesolvated structures, often have the metal ion positioned away from the center of the aryl ring and toward the pyrrole ring.…”

mentioning

confidence: 99%

Dissociations of Complexes Between Monovalent Metal Ions and Aromatic Amino Acid or Histidine

Shoeib

Zhao

Aribi³

et al. 2012

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Abstract. The fragmentations of [AA + M] + complexes, where AA 0 Phe, Tyr, Trp, or His, and M is a monovalent metal (Li, Na, or Ag), have been exhaustively studied through collision-induced dissociation (CID) and through deuterium labeling. Dissociations of the Li-and Ag-containing complexes gave a large number of fragment ions; by contrast, the sodium/amino acid complexes have lower binding energies, and dissociation resulted in much simpler spectra, with loss of the entire ligand dominating. Unambiguous assignments of these fragment ions were made and formation mechanisms are proposed. Of particular interest are fragmentations in which the charge was retained on the organic fragment and the metal was lost, either as a metal hydride (AgH) or hydroxide (LiOH) or as the silver atom (Ag

show abstract

Solution- and Solid-State Evidence for Alkali Metal Cation−π Interactions with Indole, the Side Chain of Tryptophan

Cited by 119 publications

References 16 publications

Identification of a potential metal cation–π binding site in the structure of a thermophilicBacillus stearothermophilustriosephosphate isomerase mutant

Identification of a potential metal cation–π binding site in the structure of a thermophilicBacillus stearothermophilustriosephosphate isomerase mutant

Synthetic receptors as models for alkali metal cation-π binding sites in proteins

Dissociations of Complexes Between Monovalent Metal Ions and Aromatic Amino Acid or Histidine

Contact Info

Product

Resources

About