title: Design and synthesis of heterobimetallic donor-acceptor chemodosimetric ensembles for the detection of sulfhydryl-containing amino acids and peptides.
abstract: A competitive indicator displacement assay has been successfully developed for the ratiometric determination of sulfhydryl-containing amino acids and peptides using heterobimetallic donor-acceptor complexes as chemodosimetric ensembles. Chromotropic cis-[ML2(CN)2](M = FeII, RuII, OsII; L = diimine) are used as signaling indicators and PtII(DMSO)Cl2 acceptor moiety is used as the receptor for the sulfhydryl-containing analytes. A series of three heterobimetallic donor-acceptor complexes: cis-FeII(bpy)2[CN-PtII(DMSO)Cl2]2 (1), cis-Ru(II)(bpy)2[CN-PtII(DMSO)Cl2]2 (2) and cis-Os(II)(bpy)2[CN-PtII(DMSO)Cl2]2 (3) are synthesized and characterized by X-ray crystallography. All the three ensembles are able to produce specific colorimetric/fluorimetric responses to sulfhydryl-containing amino acids (cysteine, homocysteine and methionine) as well as the sulfhydryl-containing small peptide glutathione. The mechanism of the competitive displacement assay is evaluated by examining the thermodynamics of formation of the donor-acceptor linkage and adducts between the acceptor metal and the sulfhydryl-containing analytes as well as by systematic variation of the donor and acceptor metals in the chemodosimetric ensembles.
authors.affiliation: Department of Biology & Chemistry, City University of Hong Kong, 83 Tat Chee Ave., Hong Kong SAR, China.
authors.forename: Cheuk-Fai
authors.initials: CF
authors.lastname: Chow
authors.forename: Michael H W
authors.initials: MH
authors.lastname: Lam
authors.forename: Hongyan
authors.initials: H
authors.lastname: Sui
authors.forename: Wai-Yeung
authors.initials: WY
authors.lastname: Wong
mesh_terms: D001667:Binding, Competitive; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000737:chemistry*; D005470:Fluorometry; D005978:Glutathione / Q000737:chemistry*; D006710:Homocysteine / Q000737:chemistry*; D008715:Methionine / Q000737:chemistry*; D008956:Models, Chemical; D008968:Molecular Conformation; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D013438:Sulfhydryl Compounds; D006710:Homocysteine; D008715:Methionine; D005978:Glutathione; D003545:Cysteine