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Electron capture dissociation and collision-induced dissociation of metal ion (Ag(+), Cu(2+), Zn(2+), Fe(2+), and Fe(3+)) complexes of polyamidoamine (PAMAM) dendrimers.

Kaczorowska MA, Cooper HJ - J. Am. Soc. Mass Spectrom. (2008)

Bottom Line: Complexes were of the form [PD + M + mH](5+) where PD = generation two PAMAM dendrimer with amidoethanol surface groups, M = metal ion, m = 2-4.The results suggest that complexes of Fe(3+) and Cu(2+) are coordinated via both core tertiary amines, whereas coordination of Ag(+) involves a single core tertiary amine.The Zn(2+) and Fe(2+) complexes do not appear to involve coordination by the dendrimer core.

View Article: PubMed Central - PubMed

Affiliation: School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.

ABSTRACT
The electron capture dissociation (ECD) and collision-induced dissociation (CID) of complexes of polyamidoamine (PAMAM) dendrimers with metal ions Ag(+), Cu(2+), Zn(2+), Fe(2+), and Fe(3+) were determined by Fourier transform ion cyclotron resonance mass spectrometry. Complexes were of the form [PD + M + mH](5+) where PD = generation two PAMAM dendrimer with amidoethanol surface groups, M = metal ion, m = 2-4. Complementary information regarding the site and coordination chemistry of the metal ions can be obtained from the two techniques. The results suggest that complexes of Fe(3+) and Cu(2+) are coordinated via both core tertiary amines, whereas coordination of Ag(+) involves a single core tertiary amine. The Zn(2+) and Fe(2+) complexes do not appear to involve coordination by the dendrimer core.

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ECD FT-ICR mass spectrum of (a) [PD + Ag+ + 4H]5+ ions; (b) [PD + Zn2+ + 3H]5+ ions; (c) [PD + Fe2+ + 3H]5+ ions. PD = PAMAM dendrimer.
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fig2: ECD FT-ICR mass spectrum of (a) [PD + Ag+ + 4H]5+ ions; (b) [PD + Zn2+ + 3H]5+ ions; (c) [PD + Fe2+ + 3H]5+ ions. PD = PAMAM dendrimer.

Mentions: The ECD MS/MS spectra (see Figure 2) for complexes of Ag+, Zn2+, and Fe2+ with PAMAMG2OH dendrimer ligands are very similar. As seen for protonated PAMAMG2OH dendrimer ions [21], ECD of [PD + Ag+ + 4H]5+, [PD + Zn2+ + 3H]5+, and [PD + Fe2+ + 3H]5+ complexes are dominated by cleavage at the tertiary amines and amide bonds of PAMAMG2OH ligand. Typically, fragmentation occurs in the innermost generations of the dendrimer. The fragments are detailed in Supplementary Table 2. Electron capture by the metal ions in the Zn2+ and Fe2+ complexes was not observed. A peak corresponding to [PD + 4H]4+ was observed following ECD of [PD + Ag+ + 4H]5+. That species must be the result of electron capture by Ag+. Nevertheless, no dendrimer fragments containing Ag(0) were observed. For comparison, the ECD mass spectrum of [PD + Ag+ + 2H]3+ is shown in Supplemental Figure 2. Peaks corresponding to fragments deriving from cleavage at tertiary amines and amide bonds in the inner generations dominate the spectrum. A peak corresponding to [PD + 2H]2+ was also observed. No Ag(0)-containing dendrimer fragments were observed.


Electron capture dissociation and collision-induced dissociation of metal ion (Ag(+), Cu(2+), Zn(2+), Fe(2+), and Fe(3+)) complexes of polyamidoamine (PAMAM) dendrimers.

Kaczorowska MA, Cooper HJ - J. Am. Soc. Mass Spectrom. (2008)

ECD FT-ICR mass spectrum of (a) [PD + Ag+ + 4H]5+ ions; (b) [PD + Zn2+ + 3H]5+ ions; (c) [PD + Fe2+ + 3H]5+ ions. PD = PAMAM dendrimer.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2667233&req=5

fig2: ECD FT-ICR mass spectrum of (a) [PD + Ag+ + 4H]5+ ions; (b) [PD + Zn2+ + 3H]5+ ions; (c) [PD + Fe2+ + 3H]5+ ions. PD = PAMAM dendrimer.
Mentions: The ECD MS/MS spectra (see Figure 2) for complexes of Ag+, Zn2+, and Fe2+ with PAMAMG2OH dendrimer ligands are very similar. As seen for protonated PAMAMG2OH dendrimer ions [21], ECD of [PD + Ag+ + 4H]5+, [PD + Zn2+ + 3H]5+, and [PD + Fe2+ + 3H]5+ complexes are dominated by cleavage at the tertiary amines and amide bonds of PAMAMG2OH ligand. Typically, fragmentation occurs in the innermost generations of the dendrimer. The fragments are detailed in Supplementary Table 2. Electron capture by the metal ions in the Zn2+ and Fe2+ complexes was not observed. A peak corresponding to [PD + 4H]4+ was observed following ECD of [PD + Ag+ + 4H]5+. That species must be the result of electron capture by Ag+. Nevertheless, no dendrimer fragments containing Ag(0) were observed. For comparison, the ECD mass spectrum of [PD + Ag+ + 2H]3+ is shown in Supplemental Figure 2. Peaks corresponding to fragments deriving from cleavage at tertiary amines and amide bonds in the inner generations dominate the spectrum. A peak corresponding to [PD + 2H]2+ was also observed. No Ag(0)-containing dendrimer fragments were observed.

Bottom Line: Complexes were of the form [PD + M + mH](5+) where PD = generation two PAMAM dendrimer with amidoethanol surface groups, M = metal ion, m = 2-4.The results suggest that complexes of Fe(3+) and Cu(2+) are coordinated via both core tertiary amines, whereas coordination of Ag(+) involves a single core tertiary amine.The Zn(2+) and Fe(2+) complexes do not appear to involve coordination by the dendrimer core.

View Article: PubMed Central - PubMed

Affiliation: School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.

ABSTRACT
The electron capture dissociation (ECD) and collision-induced dissociation (CID) of complexes of polyamidoamine (PAMAM) dendrimers with metal ions Ag(+), Cu(2+), Zn(2+), Fe(2+), and Fe(3+) were determined by Fourier transform ion cyclotron resonance mass spectrometry. Complexes were of the form [PD + M + mH](5+) where PD = generation two PAMAM dendrimer with amidoethanol surface groups, M = metal ion, m = 2-4. Complementary information regarding the site and coordination chemistry of the metal ions can be obtained from the two techniques. The results suggest that complexes of Fe(3+) and Cu(2+) are coordinated via both core tertiary amines, whereas coordination of Ag(+) involves a single core tertiary amine. The Zn(2+) and Fe(2+) complexes do not appear to involve coordination by the dendrimer core.

Show MeSH
Related in: MedlinePlus