Limits...
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.

Show MeSH

Related in: MedlinePlus

(a) Structure of PAMAMG2OH, second generation PAMAM dendrimer with amidoethanol surface groups and ethylenediamine core. (b) ECD and CID cleavage sites along the backbone of a PAMAM dendrimer.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2667233&req=5

grs1: (a) Structure of PAMAMG2OH, second generation PAMAM dendrimer with amidoethanol surface groups and ethylenediamine core. (b) ECD and CID cleavage sites along the backbone of a PAMAM dendrimer.

Mentions: Electrospray ionization of solutions containing equimolar concentrations of the second generation PAMAM dendrimer (ethylenediamine core, 16 amidoethanol surface groups; PAMAMG2OH) and metal ions leads to the formation of multiply-charged metal-containing ions with the general formula [PD + Mn+ + mH](n + m)+, where PD is the PAMAM dendrimer, M is the metal ion, n is the oxidation state of metal ion, and m is the number of protons. At higher concentrations of metal salt, complexes with the general formula [PD + 2Mn+ + mH](2n + m)+ and [PD + 3Mn+ +mH](3n + m)+ were observed, however the relative abundances of these complexes were much lower than those containing a single metal ion. The results presented here were obtained for [PD + Mn+ + mH]5+ precursor ions, however similar fragmentation behavior (both ECD and CID) was observed for all charge states. (For comparison, the ECD and CID mass spectra of [PD + Cu2+ + 2H]4+ and [PD + Ag+ + 2H]3+ ions are shown in Supplementary Figures 1–4, which can be found in the electronic version of this article). The structure of PAMAMG2OH is shown in Scheme 1a. The notation system for representing fragmentation sites along the backbone of the PAMAM dendrimer is shown in Scheme 1b. The system is based on that proposed by Oh and coworkers [20], and follows the conventional nomenclature for peptide and protein fragment ions [22]. Assignments are given in the form Gn(m), where subscript n refers to the generation in which fragmentation takes place and m denotes the type of fragmentation: a·x, b/y, c·/z·. Gn(in) and Gn(out) refer to fragmentation that takes place core-side of the tertiary amines. L and J concern cleavages between carbon atoms in the amidoamine branches, and K refers to cleavage surface-side of the tertiary amines. Fragment assignments were made on the basis of accurate mass measurement and verified by comparison of observed and expected isotope patterns.


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)

(a) Structure of PAMAMG2OH, second generation PAMAM dendrimer with amidoethanol surface groups and ethylenediamine core. (b) ECD and CID cleavage sites along the backbone of a PAMAM dendrimer.
© Copyright Policy
Related In: Results  -  Collection

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

grs1: (a) Structure of PAMAMG2OH, second generation PAMAM dendrimer with amidoethanol surface groups and ethylenediamine core. (b) ECD and CID cleavage sites along the backbone of a PAMAM dendrimer.
Mentions: Electrospray ionization of solutions containing equimolar concentrations of the second generation PAMAM dendrimer (ethylenediamine core, 16 amidoethanol surface groups; PAMAMG2OH) and metal ions leads to the formation of multiply-charged metal-containing ions with the general formula [PD + Mn+ + mH](n + m)+, where PD is the PAMAM dendrimer, M is the metal ion, n is the oxidation state of metal ion, and m is the number of protons. At higher concentrations of metal salt, complexes with the general formula [PD + 2Mn+ + mH](2n + m)+ and [PD + 3Mn+ +mH](3n + m)+ were observed, however the relative abundances of these complexes were much lower than those containing a single metal ion. The results presented here were obtained for [PD + Mn+ + mH]5+ precursor ions, however similar fragmentation behavior (both ECD and CID) was observed for all charge states. (For comparison, the ECD and CID mass spectra of [PD + Cu2+ + 2H]4+ and [PD + Ag+ + 2H]3+ ions are shown in Supplementary Figures 1–4, which can be found in the electronic version of this article). The structure of PAMAMG2OH is shown in Scheme 1a. The notation system for representing fragmentation sites along the backbone of the PAMAM dendrimer is shown in Scheme 1b. The system is based on that proposed by Oh and coworkers [20], and follows the conventional nomenclature for peptide and protein fragment ions [22]. Assignments are given in the form Gn(m), where subscript n refers to the generation in which fragmentation takes place and m denotes the type of fragmentation: a·x, b/y, c·/z·. Gn(in) and Gn(out) refer to fragmentation that takes place core-side of the tertiary amines. L and J concern cleavages between carbon atoms in the amidoamine branches, and K refers to cleavage surface-side of the tertiary amines. Fragment assignments were made on the basis of accurate mass measurement and verified by comparison of observed and expected isotope patterns.

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