title: Detection of bound and free IGF-1 and IGF-2 in human plasma via biomolecular interaction analysis mass spectrometry.
abstract: Insulin like growth factor (IGF)-1 and IGF-2 were assayed from human plasma via biomolecular interaction analysis mass spectrometry, utilizing antibodies as ligands for affinity retrieval. Detection of both targeted and non-targeted IGFs in the mass spectra indicated possible protein complex retrieval by the individual antibodies. A series of control experiments eliminated the possibility of analyte cross-walking between flow cells, significant antibodies cross-reactivity, and direct IGF interactions. To disrupt the putative protein complex and release its constituent proteins, plasma samples were treated with detergents. An SDS-treated plasma yielded IGF signals in a different ratio than the one observed in the mass spectra from the non-treated plasma, suggesting disruption of the protein complex, and its retrieval from non-treated plasma. Novel truncated IGF-2 variant, missing its N-terminal Alanine, was detected in all mass spectra.
authors.affiliation: Intrinsic Bioprobes Inc., 625 S. Smith Rd. Suite 22, Tempe, AZ 85281, USA. dnedelkov@intrinsicbio.com
authors.forename: Dobrin
authors.initials: D
authors.lastname: Nedelkov
authors.forename: Randall W
authors.initials: RW
authors.lastname: Nelson
authors.forename: Urban A
authors.initials: UA
authors.lastname: Kiernan
authors.forename: Eric E
authors.initials: EE
authors.lastname: Niederkofler
authors.forename: Kemmons A
authors.initials: KA
authors.lastname: Tubbs
mesh_terms: D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D008024:Ligands; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D008024:Ligands; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II