Recognition of phosphate monoester dianion by an alkoxide-bridged dinuclear zinc(ii) complex

Abstract

Recognition of phosphate monoester dianion by an alkoxide-bridged dinuclear zinc(II) complex (Zn2L3+) has been studied (L = alkoxide species of 1,3-bis[bis(pyridin-2-ylmethyl)amino]propan-2-ol). Potentiometric pH titration study disclosed a 1 : 1 phenyl phosphate complexation with Zn2L3+ in aqueous solution. The dissociation constant (= [Zn2L3+][PhOPO3(2-)]/[Zn2L3+-PhOPO3(2-)]) is an extremely small value of 2.5 x 10(-8) mol dm(-3) at 25 degrees C with I = 0.10 (NaNO3). The X-ray crystal analysis of the dizinc(II) complex with p-nitrophenyl phosphate showed that the phosphate dianion binds as a bridging ligand to the two zinc(II) ions.

Advances in purification and separation of posttranslationally modified proteins

“…It can be used to label proteins in standard SDSpolyacrylamide gels or 2-D gels and the staining procedure has been optimized [67]. The second florescent dye is based on Phos-tag (http://www.phos-tag.com/; [68]), an alkoxide-bridged dinuclear metal (usually Zn 2+ and Mn 2+) complex. These tags preferentially capture phosphomonoester dianions bound to Ser, Thr and Tyr residues.…”

A Peptide Microarray for the Detection of Protein Kinase Activity in Cell Lysate

“…Phos-tag is a zinc(II) chelate compound, which binds to the phosphate group. 20 In this study, this compound was applied to the detection of phosphorylated peptide on a glass slide. To examine whether or not the Phostag recognizes the phosphate group regardless of the phosphoamino acid types, we synthesized peptides containing phosphoserine, threonine, or tyrosine (as positive controls), respectively (Table 1).…”

Phos-tag chemistry

“…In addition, the 1:1 formation of the dizinc(II) complex and an inorganic phosphate dianion (HOPO 3 2-) was clearly detected by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) based on a characteristic mass shift and a total-charge change of the phosphate (from -2 to +1). This finding introduced a new procedure for the analysis of phosphorylated compounds using the dizinc(II) complex as an MS probe.…”