Molecular recognition of sugars by lanthanide (III) complexes of a conjugate of N, N-bis[2-[bis[2-(1, 1-dimethylethoxy)-2-oxoethyl]amino]ethyl]glycine and phenylboronic acid.
A novel conjugate of phenylboronic acid and an Ln(DTPA) derivative, in which the central acetate pendant arm was replaced by the methylamide of L-lysine, was synthesized and characterized. The results of a fit of variable (17)O NMR data and a (1)H NMRD profile show that the water residence lifetime of the Gd(III) complex (150 ns) is shorter than that of the parent compound Gd(DTPA)(2-) (303 ns). Furthermore, the data suggest that several water molecules in the second coordination sphere of Gd(III) contribute to the relaxivity of the conjugate. The Ln(III) complexes of this conjugate are highly suitable for molecular recognition of sugars. The interaction with various sugars was investigated by (11)B NMR spectroscopy. Thanks to the thiourea function that links the phenylboronic acid targeting vector with the DTPA derivative, the interactions are stronger than that of phenylboronic acid itself. In particular, the interaction with N-propylfructosamine, a model for the glucose residue in glycated human serum albumin (HSA), is very strong. Unfortunately, the complex also shows a rather strong interaction with hexose-free HSA (K(A) = 705 +/- 300).
Battistini
Elisa
E
Biocatalysis and Organic Chemistry, Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.
Mortillaro
Armando
A
Aime
Silvio
S
Peters
Joop A
JA
D001897:Boronic Acids; D002241:Carbohydrates / Q000032:analysis*; D003287:Contrast Media; D019270:Fructosamine / Q000032:analysis; D005682:Gadolinium; D019786:Gadolinium DTPA; D005947:Glucose / Q000032:analysis; D006801:Humans; D028581:Lanthanoid Series Elements; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009942:Organometallic Compounds; D004369:Pentetic Acid; D012709:Serum Albumin / Q000032:analysis
D001897:Boronic Acids; D002241:Carbohydrates; D003287:Contrast Media; D028581:Lanthanoid Series Elements; D009942:Organometallic Compounds; D012709:Serum Albumin; D019270:Fructosamine; D004369:Pentetic Acid; D005682:Gadolinium; D005947:Glucose; D019786:Gadolinium DTPA; C010686:benzeneboronic acid