Labeling of adenovirus particles with PARACEST agents

Olga Vasalatiy, Robert D. Gerard, Piyu Zhao, Xiankai Sun, A. Dean Sherry

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

Recombinant adenovirus type 5 particles (AdCMVLuc) were labeled with two different bifunctional ligands capable of forming stable complexes with paramagnetic lanthanide ions. The number of covalently attached ligands varied between 630 and 1960 per adenovirus particle depending upon the chemical reactivity of the bifunctional ligand (NHS ester versus isothiocyanide), the amount of excess ligand added, and the reaction time. The bioactivity of each labeled adenovirus derivative, as measured by the ability of the virus to infect cells and express luciferase, was shown to be highly dependent upon the number of covalently attached ligands. This indicates that certain amino groups, likely on the surface of the adenovirus fiber protein where cell binding is known to occur, are critical for viral attachment and infection. Addition of 177Lu3+ to chemically modified versus control viruses demonstrated a significant amount of nonspecific binding of 177Lu3+ to the virus particles that could not be sequestered by addition of excess DTPA. Thus, it became necessary to implement a prelabeling strategy for conjugation of preformed lanthanide ligand chelates to adenovirus particles. Using preformed Tm3+-L2, a large number of chelates having chemical exchange saturation transfer (CEST) properties were attached to the surface residues of AdCMVLuc without nonspecific binding of metal ions elsewhere on the virus particle. The potential of such conjugates to act as PARACEST imaging agents was tested using an on-resonance WALTZ sequence for CEST activation. A 12% decrease in bulk water signal intensity was observed relative to controls. This demonstrates that viral particles labeled with PARACEST-type imaging agents can potentially serve as targeted agents for molecular imaging.

Original languageEnglish (US)
Pages (from-to)598-606
Number of pages9
JournalBioconjugate Chemistry
Volume19
Issue number3
DOIs
StatePublished - Mar 2008

Fingerprint

Adenoviridae
Labeling
Ligands
Viruses
Virion
Lanthanoid Series Elements
Rare earth elements
Ions
Molecular imaging
Imaging techniques
Chemical reactivity
Pentetic Acid
Molecular Imaging
Virus Diseases
Bioactivity
Luciferases
Protein Binding
Metal ions
Esters
Metals

ASJC Scopus subject areas

  • Chemistry(all)
  • Organic Chemistry
  • Clinical Biochemistry
  • Biochemistry, Genetics and Molecular Biology(all)
  • Biochemistry

Cite this

Labeling of adenovirus particles with PARACEST agents. / Vasalatiy, Olga; Gerard, Robert D.; Zhao, Piyu; Sun, Xiankai; Sherry, A. Dean.

In: Bioconjugate Chemistry, Vol. 19, No. 3, 03.2008, p. 598-606.

Research output: Contribution to journalArticle

Vasalatiy, Olga ; Gerard, Robert D. ; Zhao, Piyu ; Sun, Xiankai ; Sherry, A. Dean. / Labeling of adenovirus particles with PARACEST agents. In: Bioconjugate Chemistry. 2008 ; Vol. 19, No. 3. pp. 598-606.
@article{4f74a7e0addc4370b3273c4486535a81,
title = "Labeling of adenovirus particles with PARACEST agents",
abstract = "Recombinant adenovirus type 5 particles (AdCMVLuc) were labeled with two different bifunctional ligands capable of forming stable complexes with paramagnetic lanthanide ions. The number of covalently attached ligands varied between 630 and 1960 per adenovirus particle depending upon the chemical reactivity of the bifunctional ligand (NHS ester versus isothiocyanide), the amount of excess ligand added, and the reaction time. The bioactivity of each labeled adenovirus derivative, as measured by the ability of the virus to infect cells and express luciferase, was shown to be highly dependent upon the number of covalently attached ligands. This indicates that certain amino groups, likely on the surface of the adenovirus fiber protein where cell binding is known to occur, are critical for viral attachment and infection. Addition of 177Lu3+ to chemically modified versus control viruses demonstrated a significant amount of nonspecific binding of 177Lu3+ to the virus particles that could not be sequestered by addition of excess DTPA. Thus, it became necessary to implement a prelabeling strategy for conjugation of preformed lanthanide ligand chelates to adenovirus particles. Using preformed Tm3+-L2, a large number of chelates having chemical exchange saturation transfer (CEST) properties were attached to the surface residues of AdCMVLuc without nonspecific binding of metal ions elsewhere on the virus particle. The potential of such conjugates to act as PARACEST imaging agents was tested using an on-resonance WALTZ sequence for CEST activation. A 12{\%} decrease in bulk water signal intensity was observed relative to controls. This demonstrates that viral particles labeled with PARACEST-type imaging agents can potentially serve as targeted agents for molecular imaging.",
author = "Olga Vasalatiy and Gerard, {Robert D.} and Piyu Zhao and Xiankai Sun and Sherry, {A. Dean}",
year = "2008",
month = "3",
doi = "10.1021/bc7002605",
language = "English (US)",
volume = "19",
pages = "598--606",
journal = "Bioconjugate Chemistry",
issn = "1043-1802",
publisher = "American Chemical Society",
number = "3",

}

TY - JOUR

T1 - Labeling of adenovirus particles with PARACEST agents

AU - Vasalatiy, Olga

AU - Gerard, Robert D.

AU - Zhao, Piyu

AU - Sun, Xiankai

AU - Sherry, A. Dean

PY - 2008/3

Y1 - 2008/3

N2 - Recombinant adenovirus type 5 particles (AdCMVLuc) were labeled with two different bifunctional ligands capable of forming stable complexes with paramagnetic lanthanide ions. The number of covalently attached ligands varied between 630 and 1960 per adenovirus particle depending upon the chemical reactivity of the bifunctional ligand (NHS ester versus isothiocyanide), the amount of excess ligand added, and the reaction time. The bioactivity of each labeled adenovirus derivative, as measured by the ability of the virus to infect cells and express luciferase, was shown to be highly dependent upon the number of covalently attached ligands. This indicates that certain amino groups, likely on the surface of the adenovirus fiber protein where cell binding is known to occur, are critical for viral attachment and infection. Addition of 177Lu3+ to chemically modified versus control viruses demonstrated a significant amount of nonspecific binding of 177Lu3+ to the virus particles that could not be sequestered by addition of excess DTPA. Thus, it became necessary to implement a prelabeling strategy for conjugation of preformed lanthanide ligand chelates to adenovirus particles. Using preformed Tm3+-L2, a large number of chelates having chemical exchange saturation transfer (CEST) properties were attached to the surface residues of AdCMVLuc without nonspecific binding of metal ions elsewhere on the virus particle. The potential of such conjugates to act as PARACEST imaging agents was tested using an on-resonance WALTZ sequence for CEST activation. A 12% decrease in bulk water signal intensity was observed relative to controls. This demonstrates that viral particles labeled with PARACEST-type imaging agents can potentially serve as targeted agents for molecular imaging.

AB - Recombinant adenovirus type 5 particles (AdCMVLuc) were labeled with two different bifunctional ligands capable of forming stable complexes with paramagnetic lanthanide ions. The number of covalently attached ligands varied between 630 and 1960 per adenovirus particle depending upon the chemical reactivity of the bifunctional ligand (NHS ester versus isothiocyanide), the amount of excess ligand added, and the reaction time. The bioactivity of each labeled adenovirus derivative, as measured by the ability of the virus to infect cells and express luciferase, was shown to be highly dependent upon the number of covalently attached ligands. This indicates that certain amino groups, likely on the surface of the adenovirus fiber protein where cell binding is known to occur, are critical for viral attachment and infection. Addition of 177Lu3+ to chemically modified versus control viruses demonstrated a significant amount of nonspecific binding of 177Lu3+ to the virus particles that could not be sequestered by addition of excess DTPA. Thus, it became necessary to implement a prelabeling strategy for conjugation of preformed lanthanide ligand chelates to adenovirus particles. Using preformed Tm3+-L2, a large number of chelates having chemical exchange saturation transfer (CEST) properties were attached to the surface residues of AdCMVLuc without nonspecific binding of metal ions elsewhere on the virus particle. The potential of such conjugates to act as PARACEST imaging agents was tested using an on-resonance WALTZ sequence for CEST activation. A 12% decrease in bulk water signal intensity was observed relative to controls. This demonstrates that viral particles labeled with PARACEST-type imaging agents can potentially serve as targeted agents for molecular imaging.

UR - http://www.scopus.com/inward/record.url?scp=41149158587&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=41149158587&partnerID=8YFLogxK

U2 - 10.1021/bc7002605

DO - 10.1021/bc7002605

M3 - Article

C2 - 18254605

AN - SCOPUS:41149158587

VL - 19

SP - 598

EP - 606

JO - Bioconjugate Chemistry

JF - Bioconjugate Chemistry

SN - 1043-1802

IS - 3

ER -