New Peptide Labels Containing Covalently Bonded Platinum(II) Centers as Diagnostic Biomarkers and Biosensors

Abstract

Water-and acid-resistant arylplatinum(II) complexes have been covalently bonded to the N-terminus of L-valine, thus providing organometallic biomolecules with excellent stability properties. Owing to the 195 Pt nucleus (I ) 1 / 2 ), these building blocks are potentially versatile biomarkers (e.g., MRI). Moreover, they display efficient in vitro biosensor characteristics since they detect SO 2 gas selectively and fully reversibly by an instantaneous change of the spectroscopic properties including a diagnostic 195 Pt NMR signal.

SPR Studies of Carbohydrate–Protein Interactions: Signal Enhancement of Low‐Molecular‐Mass Analytes by Organoplatinum(II)‐Labeling

“…Ricinus communis agglutinin from castor bean (RCA 120 ) and concanavalin A lectin from Canavalia ensiformis (Con A) were supplied by Sigma (St. Louis, USA). Compounds 1 [44] and 6 [35] were synthesized by procedures similar to those used for their iodide and bromide analogues, respectively. Compounds 8 and 10 were synthesized as described earlier.…”

“…Firstly, the monoand disaccharides d-mannose, d-glucose, d-galactose, methyl a-d-mannopyranoside, methyl b-d-galactopyranoside, and lactose were tested for their SPR responses on the lectin surfaces. The same series of free mono-and disaccharides were then labeled with the organoplatinum(ii) complex of the type [PtCl-(NCNÀR)] with the aid of the activated ester 1 (2-5;) and allowed to flow over the same lectin surfaces (NCNÀR is an abbreviation for the terdentate, monoanionic, 4-substituted 2,6-bis(dimethylaminomethylene)phenyl "pincer" ligand [35,36] ).…”

NCN–pincer palladium complexes with multiple anchoring points for functional groups

“…Yield: 146 mg (87%). 1 (14) A solution of 11 (240 mg, 0.47 mmol) in 5 mL of pyridine was treated with chloro diethylphosphate (120 mg,0.70 mmol). The reddish solution was stirred for 16 h at room temperature.…”

“…Using para-functionalities, NCN-pincer platinum complexes were attached to bio-scaffolds like carbohydrates [13] and peptides [14,15]. Because of the reversible binding properties of the NCN-pincer platinum complexes with SO 2 and I 2 [1,16], and the concomitant reversible color change from colorless to orange and purple, respectively, these conjugates are interesting candidates as biomarkers and biosensors.…”

A chelating tetrapeptide rhodium complex comprised of a histidylidene residue: biochemical tailoring of an NHC-Rh hydrosilylation catalyst

“…2 This approach has furnished, for example, peptide-decorated organometallic complexes 3 and enantioselective organometallic catalysts from achiral complexes deeply buried in enzymatic pockets, 4 and it spurred 20 the development of artificial (organometallic) amino acids for de-novo peptide synthesis. 5 Based on earlier work by Erker, 6 we have recently disclosed a route to modify histidine stereospecifically to access C-bound histidine metal complexes. 7 These 25 histidylidene complexes combine the fields of N-heterocyclic carbene (NHC) 8 and peptide chemistry, 9 thus providing new opportunities for catalysis.…”