title: Ni-NTA-gold clusters target His-tagged proteins.
abstract: Addition of six histidines to recombinant proteins has proved useful in their purification by nickel-affinity columns. This technology was adapted by synthesizing the chelator for nickel (nitrilotriacetic acid, NTA) onto the surface of gold clusters. These Ni-NTA-gold clusters were shown to specifically target the 6His region of tagged proteins. Results were verified by column chromatography, dot and overlay blots, UV-Vis spectroscopy, and scanning transmission electron microscopy. A 6His-tagged adenovirus "knob" protein was also shown to maintain receptor binding activity after gold labeling. Two types of gold clusters were used: 1.4-nm Nanogold and a new 1.8-nm "PeptideGold" coated with an NTA-dipeptide-thiol. These novel labels should be useful in site-specific high-resolution EM labeling, as well as in metallographic development, detection in the light microscope, or direct visualization.
authors.affiliation: Biology Department, Brookhaven National Laboratory, Upton, New York 11973, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Hainfeld
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.forename: C M
authors.initials: CM
authors.lastname: Halsey
authors.forename: P
authors.initials: P
authors.lastname: Freimuth
authors.forename: R D
authors.initials: RD
authors.lastname: Powell
mesh_terms: D000256:Adenoviridae / Q000737:chemistry; D015153:Blotting, Western; D002846:Chromatography, Affinity / Q000379:methods*; D005544:Forecasting; D006046:Gold / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D017348:Microscopy, Electron, Scanning Transmission / Q000379:methods; D015335:Molecular Probes / Q000138:chemical synthesis; D009532:Nickel / Q000737:chemistry; D009571:Nitrilotriacetic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*; D011991:Receptors, Virus / Q000378:metabolism; D011994:Recombinant Proteins; D015678:Viral Structural Proteins / Q000302:isolation & purification*
chemical_list: D015335:Molecular Probes; D009942:Organometallic Compounds; D011991:Receptors, Virus; D011994:Recombinant Proteins; D015678:Viral Structural Proteins; C088321:nickel nitrilotriacetic acid; D006639:Histidine; D006046:Gold; D009532:Nickel; D009571:Nitrilotriacetic Acid